vacuum caps
Skip itBrand-locked demand (top 5 brands take 98% of clicks) — this niche doesn't clear our bar today.
Conversion
Incredible13.2%search→purchase rate — share of searches ending in a sale
Returns
Great1.1%return rate — above 6% kills the launch gate
Review moat
Good603.2avg incumbent reviews — the moat a new listing must climb
Growth
Okay+20.0%90-day search growth — must beat 0% to launch
Avg price
Okay$11.58avg listing price — sweet spot $15–$100
Price range
Okay$6.50–$19.79cheapest to priciest tracked listing — scored on the share inside $15–$100
Market size
Okay$156K$156K/yr · 102K searches
Competition
Bad72%top-5 click share — a locked-up shelf
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Brand share
Bad98%top-5 brand share — brand-locked demand
Competition
The top 5 products capture 72% of clicks — a locked-up shelf that new listings rarely crack.Brands
6 flat
Sellers
23
Top-5 brand share
98%
Open market
0%
- Easily59%
- BUSY-CORNER29%
- ISPINNER4%
- BUIYLV4%
- Dorman2%
- MINIMARU2%
- 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 15 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Rubber Vacuum Caps Plug Kit 102 PCS Assorted Vacuum Plugs Hose End Caps Assortment Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8
Easily$9.094.7★1,386 rev
Rubber Vacuum Caps Plug Kit 63 PCS Assorted Vacuum Plugs Hose End Caps Assortment Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8
Easily$6.934.7★373 rev
BUSY-CORNER 80 Pieces Vacuum Cap Assortment Rubber Dropper ID from 5/32 to 3/8 Sizes Hose Caps Kit for Carburetor Manifold (Black)
BUSY-CORNER$7.554.7★1,427 rev
110 PCS Vacuum Caps Assortment Vacuum Plugs Hose End Cap Rubber Vacuum Caps Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8 1/2 5/8
BUSY-CORNER$10.044.7★394 rev
Vacuum Caps Rubber Plug Kit - 202 PCS 8 Size Assorted Vacuum Plugs Hose End Caps Assortment Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8
Easily$16.014.6★361 rev
Newest
by launch date
118 Pcs Vacuum Caps Assortment 10 Sizes Rubber Vacuum Caps Kit Vacuum Plugs Hose End Cap for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8 1/2 5/8
Easily$13.5840 rev
115PCS Nylon Vacuum Connectors 63 PCS Assorted Vacuum Plugs Hose End Caps Assortment Kit Black
Easily$14.81105 rev
110 PCS Vacuum Caps Assortment Vacuum Plugs Hose End Cap Rubber Vacuum Caps Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8 1/2 5/8
BUSY-CORNER$10.04394 rev
Rubber Vacuum Cap 177-Piece 12 Sizes Assortment Set Automotive Carb Line & Hose Caps Kit for Carburetor Manifold Automotive 3/16 5/16 1/4 5/32 3/8 1/8 1/2
MINIMARU$18.4544 rev
Vacuum Caps Rubber Plug Kit - 202 PCS 8 Size Assorted Vacuum Plugs Hose End Caps Assortment Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8
Easily$16.01361 rev
Trending
90-day click momentum
80PCS Vacuum Hose Caps Connector Assortment 6 Sizes Black Rubber Cap Automotive Topomatic Replacement Parts for Carburetor Vacuum Plugs Intake Manifold Vacuum Fitting
BUIYLV$9.214.7★
ISPINNER 60pcs Rubber Vacuum Caps Assortment Kit Hose End Caps for Carburetor Manifold Automotive 3/16 5/32 7/32 1/4 5/16 3/8
ISPINNER$6.984.6★
Rubber Vacuum Caps Plug Kit 63 PCS Assorted Vacuum Plugs Hose End Caps Assortment Kit for Carburetor Manifold Automotive 3/16 5/16 7/32 1/4 5/32 3/8 1/8
Easily$6.934.7★
BUSY-CORNER 120 Pieces Rubber Vacuum Cap Assortment 10 Sizes Tube OD from 1/8 to 1/2 Sizes Automotive Carb Line Hose Caps Kit for Carburetor Manifold
BUSY-CORNER$16.814.7★
115PCS Nylon Vacuum Connectors 63 PCS Assorted Vacuum Plugs Hose End Caps Assortment Kit Black
Easily$14.814.7★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — +20.0% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.7×
Reviews
What buyers praise and complain about, mined from review topics.What buyers love
“Good quality, nice selection of sizes, arrived on time”
“They fit perfectly on multiple vehicles”
“As advertised”
“Great value”
“Works perfect”
“Very handy and complet”
“Durable”
“Just what I needed”
“Yep they're plugs like they are supposed to be”
“High Quality Materials”
What buyers complain about
“They are literally falling apart”
“practically fell off causing a major vacuum leak”
“these are cheap”
“Cheap rubber”
“Too hard”
“I won't use these on my vehicles anymore because the material seems to crack in about 4 to 6 months”
“Just wish they included more large sizes”
“these caps bio-digrade in a few months and become very rubber staining on hands, cloth etc”
“brittle falling apart”