---
title: "Spectra Flange 21mm — $359K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/baby-products/spectra-flange-21mm"
last_updated: "2026-08-09T08:12:09.048Z"
locale: en
meta:
description: "Niche score 41/100 · $359K/yr market · 135K searches/yr · $15.66 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 41/100 · $359K/yr market · 135K searches/yr · $15.66 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Spectra Flange 21mm — $359K/yr Amazon US Niche (2026) - Flapen"
---
# **spectra flange 21mm**
**Skip it**
A concentrated shelf (top 5 take 78% of clicks) — this niche doesn't clear our bar today.
Market size 54Growth 19Conversion 98Competition 18Returns 22Price range 71Avg price 77Brand share 22Review moat 39Quality gap 40
**Conversion**
**Incredible****17.0%**
search→purchase rate — share of searches ending in a sale
**Avg price**
**Great****$15.66**
avg listing price — sweet spot $15–$100
**Price range**
**Good****$7.97–$32.51**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Market size**
**Good****$359K**
$359K/yr · 135K searches
**Quality gap**
**Okay****4.5★**
avg incumbent rating — lower means beatable quality
**Review moat**
**Okay****2,565.92**
avg incumbent reviews — the moat a new listing must climb
**Brand share**
**Bad****91%**
top-5 brand share — brand-locked demand
**Returns**
**Bad****6.0%**
return rate — above 5% kills the launch gate
**Growth**
**Bad****-11.5%**
90-day search growth — must beat 0% to launch
**Competition**
**Bad****78%**
top-5 click share — a locked-up shelf
**Signals**[** High Returns**](https://flapen.com/research/niches?market=us&signal=high_returns "Return rate > 5%")
According to Flapen's Amazon United States niche tracking, spectra flange 21mm is a $359K/yr Amazon United States market (135K searches/yr). The top 5 brands hold 91% of demand. Verdict: Skip it — 41/100.
Data updated Jul 12, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **spectra flange 21mm market data**
- **Units sold / yr**
- **25K–30K**
- avg 2,500–3,000/product
- **Revenue / yr**
- **$392K–$470K**
- units × avg price
- **Conversion rate**
- **17.0%**
- **Avg BSR**
- **#68**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **92%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **39 months**
- **Avg seller age**
- **147 days**
## **Competition & brand share**
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%**
Top 20: 100%
**Top-5 click share**
**78%**
Top 20: 100%
**Open market**
**6%**
- Maymom51% - Momstouch16% - Hranio13% - Suniceme8% - PUMPMOM-US4% - MilkFlow3% - Open — no brand owns it (3 brands, 6%)
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -11.5% search growth over the last 90 days.
4K3K seasonSepDecMarJunAugNovMarMay
No pronounced peak months · busiest ÷ quietest = 1.2×
[**Open Trend **](https://flapen.com/research/us/baby-products/spectra-flange-21mm/trend)
## **Top spectra flange 21mm search terms**
- **spectra flange 21mm**28K/yr-14.0%17.1% conv. - **21 mm flange spectra**23K/yr+3.1%18.0% conv. - **21mm flange spectra**23K/yr-19.2%17.2% conv. - **spectra 21mm flange**22K/yr-16.4%17.8% conv. - **spectra 21mm flange set**12K/yr+3.8%16.0% conv. - **21mm flange**6K/yr-18.2%7.8% conv. - **21 flange spectra**6K/yr-6.5%18.2% conv. - **21 mm flange**3K/yr-12.1%7.3% conv. - **spectra s1 flange 21mm**3K/yr-5.0%17.7% conv. - **spectra flanges 21mm**2K/yr-19.5%13.7% conv. [**All search terms **](https://flapen.com/research/us/baby-products/spectra-flange-21mm/search-terms)
## **Top spectra flange 21mm products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%10%$36K20%$72K30%$108K40%$144K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 12 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Maymom 21mm Flange and Duckbill Valve Compatible with Spectra S1 S2 9 Plus Replacment Pump Parts Not Original Spectra Flange Duckbill Valve**Maymom**$18.80**4.6★6,022 rev](https://www.amazon.com/dp/B0863NBHRX) [2**Hranio Breast Pump Parts Compatible with 21mm Spectra Flange 21mm Spectra Replacement Pump Parts s1 s2 (Flange 21mm 2 Pcs)**Hranio**$9.80**4.5★217 rev](https://www.amazon.com/dp/B0D93LMZS7) [3**Momstouch 21mm Flange and Duckbill Valve Compatible with Spectra S1 S2 9 Plus Breastpump Replacement to Spectra Pump Parts Not Original Replace Accessories.**Momstouch**$16.74**4.3★592 rev](https://www.amazon.com/dp/B0CKQK8GWG) [4**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**$16.55**4.7★7,932 rev](https://www.amazon.com/dp/B078PJPLXL) [5**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**$7.97**4.5★971 rev](https://www.amazon.com/dp/B0CW1VDP9D)
**~~View all top sellers →~~**
### **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**$11.18**75 rev1y ago](https://www.amazon.com/dp/B0FCSWCX3N) [**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**$8.22**129 rev1y ago](https://www.amazon.com/dp/B0DXTF63LS) [**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**$20.08**611 rev1y ago](https://www.amazon.com/dp/B0DNQ49L24) [**Hranio Breast Pump Parts Compatible with 21mm Spectra Flange 21mm Spectra Replacement Pump Parts s1 s2 (Flange 21mm 2 Pcs)**Hranio**$9.80**217 rev2y ago](https://www.amazon.com/dp/B0D93LMZS7) [**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**$7.97**971 rev2y ago](https://www.amazon.com/dp/B0CW1VDP9D)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**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**$20.08**4.4★**▲ 232%**](https://www.amazon.com/dp/B0DNQ49L24) [**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**$8.22**4.4★**▲ 145%**](https://www.amazon.com/dp/B0DXTF63LS) [**21mm Flange and Duckbill Valve for S1/S2/9+ Flange Inserts for Spectra Replacement Pump Parts (2-Pack) - Not Original Spectra Accessories**MilkFlow**$11.18**4.3★**▲ 114%**](https://www.amazon.com/dp/B0FCSWCX3N) [**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**$16.55**4.7★**▲ 50%**](https://www.amazon.com/dp/B078PJPLXL) [**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**$15.66**4.6★**▲ 49%**](https://www.amazon.com/dp/B0CM61MNDH)
**~~View all trending →~~**
## **What buyers say about spectra flange 21mm**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**31%
*“fit my pump no problem”*
**Quality-Overall**12%
*“Amazing quality flanges”*
**Advertised Vs Actual Product**9%
*“Exactly what I needed”*
**Comfort-Overall**7%
*“Better fit, less discomfort, and a much more positive experience overall”*
**Breastfeeding Friendly**6%
*“Works great with my Spectra breast pump”*
**Ease Of Cleaning**6%
*“Easy to clean”*
**Compatibility-Overall**5%
*“Good quality and truly is compatible”*
**Value For Money**5%
*“Very affordable”*
**Ease Of Use**3%
*“easy to use”*
**Durability**3%
*“Its durable and easy to wash and sterilize”*
### **What buyers complain about **
**Size-Overall**26%
*“they seem tiny”*
**Quality-Overall**13%
*“Absolutely Garbage”*
**Functionality-Overall**13%
*“Works but not too well”*
**Comfort-Overall**8%
*“Not comfortable”*
**Hard Feel**7%
*“the material is not as soft”*
**Skin Health**4%
*“Skin Shredder”*
**Breastfeeding Friendly**4%
*“Im not even getting a half ounce when I usually pump 4 to 6 ounces with each breast”*
**Leak-Proof**3%
*“They have poor fit which causes discomfort and leaking”*
**Ease Of Use**3%
*“It makes the arduous”*
**Value For Money**2%
*“You can see why these are cheaper in person”*
### **Top return reasons **
**Size-Overall**77%
**Width**6%
**Functionality-Overall**4%
**Advertised Vs Actual Product**3%
**Defective Material/Parts**3%
**Material Quality**1%
**Value For Money**1%
**Compatibility-Overall**1%
**Breastfeeding Friendly**1%
**Leak-Proof**1%
## **Common questions**
- **Is spectra flange 21mm profitable to sell on Amazon United States?**
- The niche generates $359K/yr across 12 tracked products. 90-day search growth is -11.5%. Flapen's verdict: Skip it (41/100).
- **How competitive is the spectra flange 21mm niche?**
- 9 brands and 18 sellers compete. The top 5 products take 78% of clicks and top 5 brands hold 91% of demand.
- **What do buyers complain about in spectra flange 21mm?**
- Top complaints mined from reviews: Size-Overall, Quality-Overall, Functionality-Overall. The return rate is 6.0% — above our launch gate.
- **When does demand for spectra flange 21mm peak?**
- Demand is steady year-round — the busiest month runs 1.2× the quietest.
- **What does it cost to enter the spectra flange 21mm niche?**
- Listings span $7.97–$32.51; the average listing price is $15.66 (sweet spot $15–$100). The average incumbent carries 2,566 reviews — the moat a new listing must climb.
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