spectra replacement pump parts 21mm
Skip itBrand-locked demand (top 5 brands take 100% of clicks) — this niche doesn't clear our bar today.
Conversion
Incredible13.2%search→purchase rate — share of searches ending in a sale
Avg price
Incredible$23.78avg listing price — sweet spot $15–$100
Price range
Incredible$16.74–$34.93cheapest to priciest tracked listing — scored on the share inside $15–$100
Review moat
Okay2,075.44avg incumbent reviews — the moat a new listing must climb
Quality gap
Okay4.5★avg incumbent rating — lower means beatable quality
Returns
Bad6.0%return rate — above 6% kills the launch gate
Growth
Bad-8.9%90-day search growth — must beat 0% to launch
Competition
Bad84%top-5 click share — a locked-up shelf
Market size
Bad$42K$42K/yr · 14K searches
Brand share
Bad100%top-5 brand share — brand-locked demand
Competition
The top 5 products capture 84% of clicks — a locked-up shelf that new listings rarely crack.Brands
5 falling
Sellers
8
Top-5 brand share
100%
Open market
0%
- Maymom51%
- afontoto23%
- Momstouch19%
- MilkFlow4%
- Hranio4%
- 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 9 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Maymom Pump Parts Compatible with Spectra S2 S1 Replacement Kit for Spectra Pump Parts 21mm Flange Duckbill Valve Tube Bottle Backflow Protector Not Original S2 Accessories
Maymom$32.514.6★9,124 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
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$20.084.4★611 rev
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
21mm Flange Maymom Pump Parts Compatible with Spectra S2 S1 9 Plus Breastpump Not Original Spectra S2 S1 Replacement Pump Parts Accessories Small Flange
Maymom$30.414.6★1,226 rev
Newest
by launch date
Breast Pump Accessories Compatible with Spectra S1 S2 S9 Plus Replacement Pump Parts 2 Sets with 21mm Flanges Spectra 10oz Bottles Duckbill Valves Tubing Backflow Protectors Not Original
afontoto$20.4772 rev
Pump Replacement Parts Compatible with Spectra S1/S2/9 Plus Not Original Accessories Full Set Include 21mm Flanges Valves Tubings and BottlesBackflow Protectors and Duckbills
MilkFlow$21.01378 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
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$34.93611 rev
Hranio Breast Pump Parts Compatible with Spectra Replacement Pump Parts 21mm Flange Spectra Pump Parts S1 S2 Replacements Full Set 2 Set (Full SET-21MM)
Hranio$19.0543 rev
Trending
90-day click momentumBreast Pump Accessories Compatible with Spectra S1 S2 S9 Plus Replacement Pump Parts 2 Sets with 21mm Flanges Spectra 10oz Bottles Duckbill Valves Tubing Backflow Protectors Not Original
afontoto$20.474.6★
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$34.934.4★
Hranio Breast Pump Parts Compatible with Spectra Replacement Pump Parts 21mm Flange Spectra Pump Parts S1 S2 Replacements Full Set 2 Set (Full SET-21MM)
Hranio$19.054.6★
21mm Flange Maymom Pump Parts Compatible with Spectra S2 S1 9 Plus Breastpump Not Original Spectra S2 S1 Replacement Pump Parts Accessories Small Flange
Maymom$30.414.6★
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★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -8.9% 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
“True to size”
“Amazing quality flanges”
“way better than I expected”
“Good quality and truly is compatible”
“Easy to clean”
“Better fit, less discomfort, and a much more positive experience overall”
“So far these have held up great after 10 months with the exception of replacing the duckbills when needed”
“easy to use”
“being able to wash dishes a little less allows for more time spent elsewhere”
“Very affordable”
What buyers complain about
“they seem tiny”
“they don't do a great job”
“Poor quality”
“Flawed, possibility of getting used product”
“Dont fit in the cup caddy for s2”
“Im not even getting a half ounce when I usually pump 4 to 6 ounces with each breast”
“Broke after the first use”
“Frustrating to Use”
“just deal with the connection issue”
“Shield Edges Uncomfortable/Painful”