flange insert
Skip itBrand-locked demand (top 5 brands take 100% of clicks) — this niche doesn't clear our bar today.
Conversion
Great8.3%search→purchase rate — share of searches ending in a sale
Market size
Good$607K$607K/yr · 795K searches
Returns
Okay3.1%return rate — above 6% kills the launch gate
Review moat
Okay1,674.43avg incumbent reviews — the moat a new listing must climb
Quality gap
Okay4.6★avg incumbent rating — lower means beatable quality
Avg price
Okay$9.25avg listing price — sweet spot $15–$100
Growth
Bad-9.1%90-day search growth — must beat 0% to launch
Competition
Bad93%top-5 click share — a locked-up shelf
Brand share
Bad100%top-5 brand share — brand-locked demand
Price range
Bad$7.34–$10.05cheapest to priciest tracked listing — scored on the share inside $15–$100
Competition
The top 5 products capture 93% of clicks — a locked-up shelf that new listings rarely crack.Brands
4 falling
Sellers
6
Top-5 brand share
100%
Open market
0%
- Nuliie44%
- Nursi Luna42%
- LOTBILL7%
- GOCROWEEN6%
- Open — no brand owns it (0%)
Product shelf
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 7 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Nuliie 3-in-1 Flange Sizing Kit 13/15/17/19/21mm for 24mm Electric Double Breast Pump Flange/Shield 10PCS Silicone Flange Inserts to Boost Pumping Efficiency & Comfort BPA-Free Essential for Moms
Nuliie$9.684.6★4,179 rev
Nursi Luna Flange Inserts 10PCS 13/15/17/19/21mm for 24mm Flanges/Shield of Most Pumps Flange Sizing Kit Silicone Flanges Insert Breastfeeding Essentials Kit for New Moms
Nursi Luna$10.054.6★2,006 rev
Nursi Luna Flange Sizing Kit 3-in-1 with 13/15/17/19/21mm for 24mm Electric Breast Pump Flanges/Shields 10PCS Soft Silicone Flange Inserts for More Comfortable Pumping BPA-Free Essential for Moms
Nursi Luna$9.874.6★2,081 rev
Flange Insert 13/15/17/19/21mm 10PCS Compatible with Momcozy S12 Pro/S9 Pro/S12/S9/Medela/Spectra etc Electric Breast Pump 24mm Flange/Shield Reduce 24mm Tunnel Down to Correct Size
LOTBILL$7.344.6★583 rev
Flange Inserts 13/15/17/19/21mm 5pcs Suitable for Medela Spectra 24mm Shields/Flanges Compatible with Momcozy S12 Pro/S9 Pro/S9/S12 Wearable Breast Pump Reduce 24mm Tunnel Down to Correct Size
GOCROWEEN$8.014.4★2,046 rev
Newest
by launch date
Nuliie 5-in-1 Flange Sizing Kit 12/14/16/18/20mm for 24mm Flange/Shield of Most Pumps 10PCS Silicone Flange Inserts to Boost Pumping Efficiency & Comfort BPA-Free Pump Essential for Moms
Nuliie$9.90445 rev
Nursi Luna Flange Sizing Kit with 13/15/17/19/21mm for 24mm Electric Breast Pump Flanges/Shields 10PCS Soft Silicone Flange Inserts for Enhanced Pumping Comfort BPA-Free Pump Essential for Moms
Nursi Luna$9.86381 rev
Nursi Luna Flange Sizing Kit 3-in-1 with 13/15/17/19/21mm for 24mm Electric Breast Pump Flanges/Shields 10PCS Soft Silicone Flange Inserts for More Comfortable Pumping BPA-Free Essential for Moms
Nursi Luna$9.872,081 rev
Nursi Luna Flange Inserts 10PCS 13/15/17/19/21mm for 24mm Flanges/Shield of Most Pumps Flange Sizing Kit Silicone Flanges Insert Breastfeeding Essentials Kit for New Moms
Nursi Luna$10.052,006 rev
Nuliie 3-in-1 Flange Sizing Kit 13/15/17/19/21mm for 24mm Electric Double Breast Pump Flange/Shield 10PCS Silicone Flange Inserts to Boost Pumping Efficiency & Comfort BPA-Free Essential for Moms
Nuliie$9.684,179 rev
Trending
90-day click momentumNuliie 5-in-1 Flange Sizing Kit 12/14/16/18/20mm for 24mm Flange/Shield of Most Pumps 10PCS Silicone Flange Inserts to Boost Pumping Efficiency & Comfort BPA-Free Pump Essential for Moms
Nuliie$9.904.5★
Nursi Luna Flange Inserts 10PCS 13/15/17/19/21mm for 24mm Flanges/Shield of Most Pumps Flange Sizing Kit Silicone Flanges Insert Breastfeeding Essentials Kit for New Moms
Nursi Luna$10.054.6★
Flange Insert 13/15/17/19/21mm 10PCS Compatible with Momcozy S12 Pro/S9 Pro/S12/S9/Medela/Spectra etc Electric Breast Pump 24mm Flange/Shield Reduce 24mm Tunnel Down to Correct Size
LOTBILL$7.344.6★
Flange Inserts 13/15/17/19/21mm 5pcs Suitable for Medela Spectra 24mm Shields/Flanges Compatible with Momcozy S12 Pro/S9 Pro/S9/S12 Wearable Breast Pump Reduce 24mm Tunnel Down to Correct Size
GOCROWEEN$8.014.4★
Nursi Luna Flange Sizing Kit with 13/15/17/19/21mm for 24mm Electric Breast Pump Flanges/Shields 10PCS Soft Silicone Flange Inserts for Enhanced Pumping Comfort BPA-Free Pump Essential for Moms
Nursi Luna$9.864.6★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -9.1% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.3×
Reviews
What buyers praise and complain about, mined from review topics.What buyers love
“Like the sizer”
“One thing that really stood out to me was how well-made”
“This made it so easy for me”
“Good price”
“So comfortable”
“The little cleaning sponge is wonderful”
“Very helpful and useful for breastfeeding”
“It performs exactly as intended”
“Compatible with Frida Mom manual pump”
“durable”
What buyers complain about
“Does NOT fit”
“Poor quality”
“Incompatible with Elvie Stride”
“they are kind of a pain to insert and clean and the output isnt as good as just using the correct size pump accessory”
“one of the flange inserts tore right apart immediately after opening”
“Very uncomfortable”
“Waste of money”
“Doesnt work for me”
“Horrible product, pieces missing, and some pieces broken”
“Instructions were not clear instead they were confusing”