All are pros ,no cons. I received the little pen like tester,I followed the instructions: I opened the brake fluid reservoir cap,turned on the tester;the led light came on, I dipped it into the brake fluid,it registered correctly,easy to use,and accurate,very pleased.

The tester works well but the battery cover is not held on very well and is not sealed, make sure you don’t put the tester to far into the fluid.

Seems to work. Feels a little cheap to hold but told me my brake fluid was less than 1% of water. Its a 5 year old Model S I bought from a prior owner, wonder if he got it fixed up recently at a Tesla shop. Ive read the brake fluid should be changed every 2 years generally due to water build up. Guess I am okay though. Kinda expected the prior owners to have never taken care of these kinda things. The air filter on it certainly was filthy!

Motorists don't like paying for brake fluid flushes. This little device along with a 2 minute verbal lesson on why it is important makes that critical service much easier to appreciate. This is especially true for motorcyclists, where a small rise in water levels could lead to total brake failure when riding them hard.

I have read where these are not the most accurate devices but easy to use and the results are good enough to let you know when to change your fluid.

Works like a charm I tested with fresh brake fluid then with a drop of water the reading showed was useable but was contaminated. then with have water half brake fluid total contamination . I was the pretty confidant that the hydrometer was accurate so on to my road king both master cylinders showed total contamination and was due for flushing of the entire system

This actually works surprisingly well. I had asked an acquaintance in the field, and he said that others had attested to their function, but I was skeptical, myself.Just make sure it's fully dry before you use it, or you could get a false negative and contaminate the system.

I liked the price. These sort of instruments were very expensive about ten years ago, but now this precise and potentially life saving preventative tool can be had for a song. That being said, the toolfeels cheap; lose fitting cap, material feels brittle, the operation of the readout lights is poorly lit for working in open daylight. It feels not long lasting, then again, for the affordable price, to replace it in the future will not hurt the wallet too much.

I have only had this a week or so and I have tested both of my cars and one or two others. It has worked as expected with easy-to-read LED lights showing the percent of moisture in your brake fluid.

Great product. I used this on my 4 wheelers to test and worked great. 2012 Polaris ATVs never changed the break fluid and of course it read above 4 percent. I tested it on new bake fluid and it read 2 percent or below. So far very happy with this new tool.