brake fluid tester
Worth a lookShows searches that convert (10.0% search→purchase), but a concentrated shelf (top 5 take 81% of clicks) keeps it on the watch list.
Conversion
Great10.0%search→purchase rate — share of searches ending in a sale
Returns
Great1.4%return rate — above 6% kills the launch gate
Review moat
Good841.38avg incumbent reviews — the moat a new listing must climb
Quality gap
Good4.4★avg incumbent rating — lower means beatable quality
Avg price
Good$12.60avg listing price — sweet spot $15–$100
Market size
Good$305K$305K/yr · 241K searches
Brand share
Okay81%top-5 brand share — brands hold most of the demand
Price range
Okay$4.47–$21.60cheapest to priciest tracked listing — scored on the share inside $15–$100
Growth
Okay+3.2%90-day search growth — must beat 0% to launch
Competition
Bad81%top-5 click share — a locked-up shelf
Competition
The top 5 products capture 81% of clicks — a locked-up shelf that new listings rarely crack.Brands
13 rising
Sellers
18
Top-5 brand share
81%
Open market
15%
- ITEQ24%
- KAIWEETS20%
- Aicevoos15%
- YOGEIER11%
- ecocstm10%
- Phoenix Systems4%
- Open — no brand owns it (7 brands, 15%)
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 13 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
ITEQ Brake Fluid Liquid Tester Pen with 5 LED Indicators Calibrated For DOT3 DOT4 Brake Fluid
ITEQ$13.604.4★3,954 rev
KAIWEETS Brake Fluid Tester Pen with Corrosion Resistance Probe High-Precision Brake Fluid Moisture Tester with Data Hold Function Buzzer Alarm 3 Colors Backlight Calibrated for DOT3 DOT4 DOT5.1
KAIWEETS$17.874.5★517 rev
Aicevoos NF Brake Fluid Tester Pen Brake Fluid Test Strips Calibrated for DOT3 DOT4 DOT-5.1 Brake Fluid
Aicevoos$12.974.5★1,213 rev
Brake Fluid Liquid Tester Pen 1PC DOT 3 DOT 4 DOT 5.1 Brake Fluid Liquid Tester Pen Car Diagnostic Testing Tool with 5 LED Indicators Hydraulic Fluid Liquid Oil Moisture Analyzer
YOGEIER$6.034.2★1,235 rev
ecocstm Brake Fluid Tester Brake Fluid Moisture Tester Brake Fluid Liquid Tester Pen with 5 LED Indicators Auto Brake Diagnostic Checker Tool for DOT3 DOT4 DOT5.1 Brake Fluid
ecocstm$5.554.2★239 rev
Newest
by launch date
Xtruck Brake Fluid Tester Pen with Corrosion Resistance Probe Brake Fluid Moisture Tester with Screen Display Alarm Oil Fluid Tester Calibrated for DOT3 DOT4 DOT5.1 Brake Fluid
Xtruck$10.9087 rev
FSTURIOS 2PCS Brake Fluid Liquid Tester Pen DOT 3 DOT 4 DOT 5.1 Brake Fluid Diagnostic Testing Pen Vehicle High-Precision Hydraulic Liquid Oil Moisture Analyzer with 5 LED Indicators
FSTURIOS$7.17131 rev
POROMETISTO FT01 Brake Fluid Tester with Flashlight Built-in Calibration Resistor Brake Fluid Moisture Tester with 8.5-Inch Corrosion Resistance Probe and Data Hold for DOT3 DOT4 DOT5.1
POROMETISTO$20.46188 rev
TESMEN TBF-300 Brake Fluid Tester with 8.5-Inch Corrosion Resistance Gooseneck Probe Testing for DOT3 DOT4 DOT5.1 Brake Fluid Tester Pen with Light Data Hold Backlight Alarm for Auto Care-Green
TESMEN$21.60302 rev
ecocstm Brake Fluid Tester Brake Fluid Moisture Tester Brake Fluid Liquid Tester Pen with 5 LED Indicators Auto Brake Diagnostic Checker Tool for DOT3 DOT4 DOT5.1 Brake Fluid
ecocstm$5.55239 rev
Trending
90-day click momentumecocstm Brake Fluid Tester Brake Fluid Moisture Tester Brake Fluid Liquid Tester Pen with 5 LED Indicators Auto Brake Diagnostic Checker Tool for DOT3 DOT4 DOT5.1 Brake Fluid
ecocstm$5.554.2★
Xtruck Brake Fluid Tester Pen with Corrosion Resistance Probe Brake Fluid Moisture Tester with Screen Display Alarm Oil Fluid Tester Calibrated for DOT3 DOT4 DOT5.1 Brake Fluid
Xtruck$10.904.5★
Aicevoos NF Brake Fluid Tester Pen Brake Fluid Test Strips Calibrated for DOT3 DOT4 DOT-5.1 Brake Fluid
Aicevoos$12.974.5★
FSTURIOS 2PCS Brake Fluid Liquid Tester Pen DOT 3 DOT 4 DOT 5.1 Brake Fluid Diagnostic Testing Pen Vehicle High-Precision Hydraulic Liquid Oil Moisture Analyzer with 5 LED Indicators
FSTURIOS$7.174.2★
KAIWEETS Brake Fluid Tester Pen with Corrosion Resistance Probe High-Precision Brake Fluid Moisture Tester with Data Hold Function Buzzer Alarm 3 Colors Backlight Calibrated for DOT3 DOT4 DOT5.1
KAIWEETS$17.874.5★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — +3.2% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.5×
Reviews
What buyers praise and complain about, mined from review topics.What buyers love
“handy”
“it does get the job done”
“Saves money”
“Good quality and good reliable”
“It works as advertised”
“Great way to extend the Maintenance Interval on my Tesla Model Y”
“Great, easy way to test brake fluid”
“gives efficient readings”
“coolant these are a must have”
“The battery was fresh and installed correctly”
What buyers complain about
“Broke after first use”
“bad quality”
“Didn't work”
“Questionable accuracy”
“it turned red”
“It doesnt get much easier to use”
“SHowed no water in Water”
“this tester says my brake fluid needs to be replaced”
“Ill pass thats why its only $17 youre buying a piece of junk”
“The instructions are beyond confusing”