spectra flange 21mm
Skip itA concentrated shelf (top 5 take 78% of clicks) — this niche doesn't clear our bar today.
Conversion
Incredible17.0%search→purchase rate — share of searches ending in a sale
Avg price
Great$15.66avg listing price — sweet spot $15–$100
Price range
Good$7.97–$32.51cheapest to priciest tracked listing — scored on the share inside $15–$100
Market size
Good$359K$359K/yr · 135K searches
Quality gap
Okay4.5★avg incumbent rating — lower means beatable quality
Review moat
Okay2,565.92avg incumbent reviews — the moat a new listing must climb
Returns
Okay6.0%return rate — above 6% kills the launch gate
Brand share
Bad91%top-5 brand share — brand-locked demand
Growth
Bad-11.5%90-day search growth — must beat 0% to launch
Competition
Bad78%top-5 click share — a locked-up shelf
Competition
The top 5 products capture 78% of clicks — a locked-up shelf that new listings rarely crack.Brands
9 rising
Sellers
18
Top-5 brand share
91%
Open market
6%
- Maymom51%
- Momstouch16%
- Hranio13%
- Suniceme8%
- PUMPMOM-US4%
- MilkFlow3%
- Open — no brand owns it (3 brands, 6%)
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 12 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Maymom 21mm Flange and Duckbill Valve Compatible with Spectra S1 S2 9 Plus Replacment Pump Parts Not Original Spectra Flange Duckbill Valve
Maymom$18.804.6★6,022 rev
Hranio Breast Pump Parts Compatible with 21mm Spectra Flange 21mm Spectra Replacement Pump Parts s1 s2 (Flange 21mm 2 Pcs)
Hranio$9.804.5★217 rev
Momstouch 21mm Flange and Duckbill Valve Compatible with Spectra S1 S2 9 Plus Breastpump Replacement to Spectra Pump Parts Not Original Replace Accessories.
Momstouch$16.744.3★592 rev
Maymom Wide Neck Pump Part for Spectra S1/S2 Pumps; Incl Wide Mouth Flange; Not Original Spectra Flange; Replaces Spectra Shield (21 mm Two Flanges)
Maymom$16.554.7★7,932 rev
Flange Inserts 21mm Compatible with Medela/Spectra/TSRETE/Elvie/Momcozy/Bellababy Breast Pump 24mm Shields/Flanges Reduce 24mm Nipple Tunnel Down to 21 mm 4PCS
Suniceme$7.974.5★971 rev
Newest
by launch date
21mm Flange and Duckbill Valve for S1/S2/9+ Flange Inserts for Spectra Replacement Pump Parts (2-Pack) - Not Original Spectra Accessories
MilkFlow$11.1875 rev
BALIME 21MM Wide-Mouth Flange Spectra Replacement Pump Parts for S1 S2 - BPA Free Spectra Replacement Pump Parts - Perfect for Travel & Working Moms (2-Pack)
BALIME$8.22129 rev
Pump Parts Compatible with Spectra S1/S2/9Plus/SG Breastpump Full Set Replacement Parts for Spectra Include 21mm Flange Duckbill Valve Backflow Protector Tube Bottle Not Original S1/S2 Accessories
afontoto$20.08611 rev
Hranio Breast Pump Parts Compatible with 21mm Spectra Flange 21mm Spectra Replacement Pump Parts s1 s2 (Flange 21mm 2 Pcs)
Hranio$9.80217 rev
Flange Inserts 21mm Compatible with Medela/Spectra/TSRETE/Elvie/Momcozy/Bellababy Breast Pump 24mm Shields/Flanges Reduce 24mm Nipple Tunnel Down to 21 mm 4PCS
Suniceme$7.97971 rev
Trending
90-day click momentumPump Parts Compatible with Spectra S1/S2/9Plus/SG Breastpump Full Set Replacement Parts for Spectra Include 21mm Flange Duckbill Valve Backflow Protector Tube Bottle Not Original S1/S2 Accessories
afontoto$20.084.4★
BALIME 21MM Wide-Mouth Flange Spectra Replacement Pump Parts for S1 S2 - BPA Free Spectra Replacement Pump Parts - Perfect for Travel & Working Moms (2-Pack)
BALIME$8.224.4★
21mm Flange and Duckbill Valve for S1/S2/9+ Flange Inserts for Spectra Replacement Pump Parts (2-Pack) - Not Original Spectra Accessories
MilkFlow$11.184.3★
Maymom Wide Neck Pump Part for Spectra S1/S2 Pumps; Incl Wide Mouth Flange; Not Original Spectra Flange; Replaces Spectra Shield (21 mm Two Flanges)
Maymom$16.554.7★
Momstouch 21mm Flange Compatible with Spectra S1 S2 9 Plus Synergy Gold Breastpump Replacement to Spectra Pump Parts and Flange; Not Original; Replaces Shield
Momstouch$15.664.6★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -11.5% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.2×
Reviews
What buyers praise and complain about, mined from review topics.What buyers love
“fit my pump no problem”
“Amazing quality flanges”
“Exactly what I needed”
“Better fit, less discomfort, and a much more positive experience overall”
“Works great with my Spectra breast pump”
“Easy to clean”
“Good quality and truly is compatible”
“Very affordable”
“easy to use”
“Its durable and easy to wash and sterilize”
What buyers complain about
“they seem tiny”
“Absolutely Garbage”
“Works but not too well”
“Not comfortable”
“the material is not as soft”
“Skin Shredder”
“Im not even getting a half ounce when I usually pump 4 to 6 ounces with each breast”
“They have poor fit which causes discomfort and leaking”
“It makes the arduous”
“You can see why these are cheaper in person”