2PCS Brake Fluid Liquid Tester Pen, DOT 3 DOT 4 DOT 5.1 Brake Fluid Liquid Tester Pen with 5 LED Indicators, Hydraulic Fluid Liquid Oil Moisture Analyzer, Car Diagnostic Testing Tool

These two units arrived in a 'zip lock' style bag with no instructions. It should come with at least a table to interpret the light sequences meanings.When I removed the top 'press button' portion, the press button fell right out. The printing for the light indictors meaning is printed is very light and in a VERY tiny font in a blueish grey color, instead of using a color or colors that would provide contrast and clarity.I'll use these and if they work leave the review at 3 stars because these shortcomings would be simple to correct and make the tool far more user-friendly, esp. when these are made for the DIYers out there who are not likely to use this tool regularly and would benefit from clear print on table to read the test lights indications.

Light weight and easy to function.

I bought these 2 for a real cheap price, well I've used them 3 times and have already spent more in batteries than what I paid for the 2 of them. I don't know why but with a brand new battery put in it works then a couple days later I go to use one of them and they're both dead both batteries. This being the 3rd time I know now not to leave the battery in them, not that it's that hard to do the battery covers won't stay on either. Worst purchase of the year for me, I wouldn't recommend them, hell I tried to give them away to another machanic and he didn't want them. My kids have gotten better quality prizes out of a happy meal.

Good quality works great

These work for measuring water content as described, but if the battery is left inside it will run down within a day. Fit for the purpose but would not buy again for that reason.

It does what it's supposed to do. Very practical tool to have. You do not have to change your brake fluid unnecessarily. This will give you an exact reading of your brake fluid. Just remember to stir the brake fluid in the brake reservoir before testing it. It is important to do this. Because the brake fluid is at the bottom of the reservoir, and the water or condensation is on the top. By testing just the top without stirring it up. You get a false reading maybe.

I have vehicles I do not drive a lot, like a comprised van, a snowplow used in winter. This will help you if there is water, moisture getting into the brake fluid reservoir. Then it will tell you when to change brake fluid when needed to keep the water freezing and causing you to have no brakes. This will also be worth to tell you rather than the auto repair shop telling you to change brake fluid a real money maker, when you do not need to, this way you keep them honest.