{
  "schema_version": "compare-page.v2",
  "page_id": "flange-sizes-for-willow-breast-pumps",
  "url": "https://robotrunk.com/compare/want/flange-sizes-for-willow-breast-pumps",
  "title": "Flange sizes for Willow breast pumps",
  "question": "Which flange sizes are offered for Willow breast pumps?",
  "answer": "Willow Pump Willow Go® Flange Set (2-pack): Sold in three flange sizes: 21mm, 24mm and 27mm\nWillow Pump Willow Sync Flange Set 24mm (2-pack): The flanges are 24mm.\nWillow Pump Willow Sizing Insert Set: Sizes offered are 13mm, 15mm, 17mm, 19mm, 21mm and 27mm.\nWillow Pump Breast Pump Sizing Kit: The kit provides a wide range of inserts to find the right breast pump flange fit for comfortable pumping and milk output.",
  "kind": "breastfeeding supply",
  "market": "US",
  "generated_at": "2026-10-11T19:02:49.643Z",
  "columns": [
    "Sizes",
    "Pack size",
    "Notes",
    "SKU"
  ],
  "notices": {
    "facts": "Every value in the table is a fact RoboTrunk checked, linked to the page it came from. A dash means no checked fact fills that cell.",
    "price": "Prices and stock change, so this page prints neither: each product name links to its RoboTrunk page, which shows them live."
  },
  "cited_facts": [
    {
      "ref": "p1.f1",
      "product": "Willow Pump Willow Sync Flange Set 24mm (2-pack)",
      "field": "pack size",
      "value": "Sold as a 2-pack.",
      "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p1.f2",
      "product": "Willow Pump Willow Sync Flange Set 24mm (2-pack)",
      "field": "flange size",
      "value": "The flanges are 24mm.",
      "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p1.f3",
      "product": "Willow Pump Willow Sync Flange Set 24mm (2-pack)",
      "field": "SKU",
      "value": "The SKU is PF2435.",
      "stated_as": "SKU PF2435",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p1.f4",
      "product": "Willow Pump Willow Sync Flange Set 24mm (2-pack)",
      "field": "compatibility",
      "value": "Designed for Willow Sync pumps.",
      "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p2.f1",
      "product": "Willow Pump Willow Go® Flange Set (2-pack)",
      "field": "sizes",
      "value": "Sold in three flange sizes: 21mm, 24mm and 27mm",
      "stated_as": "Willow Go's flanges come in 3 sizes so you can find your best fit.",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p2.f2",
      "product": "Willow Pump Willow Go® Flange Set (2-pack)",
      "field": "compatibility",
      "value": "24mm flanges fit sizing inserts for those measuring smaller than 21mm",
      "stated_as": "24mm flanges are compatible with sizing inserts for mamas who measure smaller than 21mm.",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p2.f3",
      "product": "Willow Pump Willow Go® Flange Set (2-pack)",
      "field": "pack size",
      "value": "Sold as a 2-pack",
      "stated_as": "Willow Go® Flange Set (2-pack)",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p4.f1",
      "product": "Willow Pump Willow Sizing Insert Set",
      "field": "Pack size",
      "value": "The sizing inserts come as a 2-pack.",
      "stated_as": "2-pack",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p4.f2",
      "product": "Willow Pump Willow Sizing Insert Set",
      "field": "Purpose",
      "value": "They are designed for the perfect fit and performance with Willow and make pumping more comfortable for mamas with smaller flange sizes.",
      "stated_as": "Designed for the perfect fit and performance with Willow, Sizing Inserts make pumping more comfortable for mamas with smaller flange sizes.",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p4.f3",
      "product": "Willow Pump Willow Sizing Insert Set",
      "field": "Available sizes",
      "value": "Sizes offered are 13mm, 15mm, 17mm, 19mm, 21mm and 27mm.",
      "stated_as": "Variant: 27mm | 10.99 USD | SKU S827",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p4.f4",
      "product": "Willow Pump Willow Sizing Insert Set",
      "field": "Identifiers",
      "value": "Each size has its own SKU, for example SZ1385 for 13mm and S827 for 27mm.",
      "stated_as": "SKU SZ1385",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p5.f1",
      "product": "Willow Pump Breast Pump Sizing Kit",
      "field": "Purpose",
      "value": "The kit provides a wide range of inserts to find the right breast pump flange fit for comfortable pumping and milk output.",
      "stated_as": "Find your perfect breast pump flange fit with a wide range of inserts designed for maximum pumping comfort and milk output.",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    },
    {
      "ref": "p5.f2",
      "product": "Willow Pump Breast Pump Sizing Kit",
      "field": "SKU",
      "value": "The kit's SKU is USK110.",
      "stated_as": "SKU USK110",
      "source_type": "listing",
      "source_url": "https://willowpump.myshopify.com/products.json",
      "source_read_at": "2026-10-11T07:27:24.617Z"
    }
  ],
  "rows": [
    {
      "rank": 1,
      "merchant": {
        "slug": "onewillow-com",
        "display_name": "onewillow.com"
      },
      "product_id": "gid://shopify/Product/6705010081885",
      "name": "Willow Pump Willow Go® Flange Set (2-pack)",
      "url": "/products/ucp/onewillow-com/6705010081885",
      "why": "Sold in three flange sizes: 21mm, 24mm and 27mm",
      "cells": [
        {
          "column": "Sizes",
          "fact": {
            "field": "sizes",
            "value": "Sold in three flange sizes: 21mm, 24mm and 27mm",
            "stated_as": "Willow Go's flanges come in 3 sizes so you can find your best fit.",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Pack size",
          "fact": {
            "field": "pack size",
            "value": "Sold as a 2-pack",
            "stated_as": "Willow Go® Flange Set (2-pack)",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Notes",
          "fact": {
            "field": "compatibility",
            "value": "24mm flanges fit sizing inserts for those measuring smaller than 21mm",
            "stated_as": "24mm flanges are compatible with sizing inserts for mamas who measure smaller than 21mm.",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "SKU",
          "fact": null
        }
      ]
    },
    {
      "rank": 2,
      "merchant": {
        "slug": "onewillow-com",
        "display_name": "onewillow.com"
      },
      "product_id": "gid://shopify/Product/7967832408157",
      "name": "Willow Pump Willow Sync Flange Set 24mm (2-pack)",
      "url": "/products/ucp/onewillow-com/7967832408157",
      "why": "The flanges are 24mm.",
      "cells": [
        {
          "column": "Sizes",
          "fact": {
            "field": "flange size",
            "value": "The flanges are 24mm.",
            "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Pack size",
          "fact": {
            "field": "pack size",
            "value": "Sold as a 2-pack.",
            "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Notes",
          "fact": {
            "field": "compatibility",
            "value": "Designed for Willow Sync pumps.",
            "stated_as": "Willow Sync Flange Set 24mm (2-pack)",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "SKU",
          "fact": {
            "field": "SKU",
            "value": "The SKU is PF2435.",
            "stated_as": "SKU PF2435",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        }
      ]
    },
    {
      "rank": 3,
      "merchant": {
        "slug": "onewillow-com",
        "display_name": "onewillow.com"
      },
      "product_id": "gid://shopify/Product/6552686755933",
      "name": "Willow Pump Willow Sizing Insert Set",
      "url": "/products/ucp/onewillow-com/6552686755933",
      "why": "Sizes offered are 13mm, 15mm, 17mm, 19mm, 21mm and 27mm.",
      "cells": [
        {
          "column": "Sizes",
          "fact": {
            "field": "Available sizes",
            "value": "Sizes offered are 13mm, 15mm, 17mm, 19mm, 21mm and 27mm.",
            "stated_as": "Variant: 27mm | 10.99 USD | SKU S827",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Pack size",
          "fact": {
            "field": "Pack size",
            "value": "The sizing inserts come as a 2-pack.",
            "stated_as": "2-pack",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "Notes",
          "fact": {
            "field": "Purpose",
            "value": "They are designed for the perfect fit and performance with Willow and make pumping more comfortable for mamas with smaller flange sizes.",
            "stated_as": "Designed for the perfect fit and performance with Willow, Sizing Inserts make pumping more comfortable for mamas with smaller flange sizes.",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "SKU",
          "fact": {
            "field": "Identifiers",
            "value": "Each size has its own SKU, for example SZ1385 for 13mm and S827 for 27mm.",
            "stated_as": "SKU SZ1385",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        }
      ]
    },
    {
      "rank": 4,
      "merchant": {
        "slug": "onewillow-com",
        "display_name": "onewillow.com"
      },
      "product_id": "gid://shopify/Product/8010761175133",
      "name": "Willow Pump Breast Pump Sizing Kit",
      "url": "/products/ucp/onewillow-com/8010761175133",
      "why": "The kit provides a wide range of inserts to find the right breast pump flange fit for comfortable pumping and milk output.",
      "cells": [
        {
          "column": "Sizes",
          "fact": null
        },
        {
          "column": "Pack size",
          "fact": null
        },
        {
          "column": "Notes",
          "fact": {
            "field": "Purpose",
            "value": "The kit provides a wide range of inserts to find the right breast pump flange fit for comfortable pumping and milk output.",
            "stated_as": "Find your perfect breast pump flange fit with a wide range of inserts designed for maximum pumping comfort and milk output.",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        },
        {
          "column": "SKU",
          "fact": {
            "field": "SKU",
            "value": "The kit's SKU is USK110.",
            "stated_as": "SKU USK110",
            "source_type": "listing",
            "source_url": "https://willowpump.myshopify.com/products.json",
            "source_read_at": "2026-10-11T07:27:24.617Z"
          }
        }
      ]
    }
  ]
}