---
title: "Products — 21mm ソケット - Flapen"
canonical_url: "https://flapen.com/research/jp/diy/21mm/products"
last_updated: "2026-08-08T08:44:33.910Z"
locale: en
meta:
  description: "Niche score 57/100 · ¥2.0M/yr market. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
  "og:description": "Niche score 57/100 · ¥2.0M/yr market. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
  "og:title": "Products — 21mm ソケット - Flapen"
---

# **21mm ソケット**

**Worth a look**

Shows low returns (0.7%), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.

Market size 95Growth 3Conversion 72Competition 68Returns 97Price range 0Avg price 0Brand share 50Review moat 75Quality gap 67

**Returns**

**Incredible****0.7%**

return rate — above 5% kills the launch gate

**Market size**

**Incredible****¥2.0M**

¥2.0M/yr · 29K searches

**Review moat**

**Good****514.72**

avg incumbent reviews — the moat a new listing must climb

**Conversion**

**Good****6.6%**

search→purchase rate — share of searches ending in a sale

**Competition**

**Good****44%**

top-5 click share — leaders hold, buyers still browse

**Quality gap**

**Good****4.3★**

avg incumbent rating — lower means beatable quality

**Brand share**

**Good****75%**

top-5 brand share — brands hold most of the demand

**Growth**

**Bad****-44.1%**

90-day search growth — must beat 0% to launch

**Avg price**

**Bad****¥1065.81**

avg listing price — sweet spot $15–$100

**Price range**

**Bad****¥407.86–¥3128.11**

cheapest to priciest tracked listing — scored on the share inside $15–$100

**Signals**[** High Price**](https://flapen.com/research/niches?market=jp&signal=high_price "Avg price > $50")

## Products