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

This is a quality tool that’s easy to use and works well.

Well made, accuracy fair but adequate for my needs. Wish it had a swivel for those cars with awkward openings. Still feel it was worth the purchase.

Before goes to the car dealership check your fluid brake with this tester, easy to use and very precise. I took my Mazda 22,000 miles they told me I have to flush the brake fluid because it was contaminated I knew they were lying, so I use the tester and the brake fluid fine.

i’ve been using this device for about five months it has worked very well at determining how bad the brake fluid is in the vehicles that come into my job and I perform a vehicle inspection on works extremely well. My only little complaint is that if you shake it a little too hard it seems to make the batteries, loose contact, and shut off, but of course there’s no reason to be shaking it or abusing this little tool. All you do is turn it on for a second and then turn it right back off just gotta be a little careful with it and don’t beat it up in this tool will work great for years

Works perfectly and at a good price.

Love the fact it takes common cells instead of button cell batteries. Very user friendly due to the color coded thresholds. A must for newer vehicles that require frequent brake fluid changes. This way you aren't needlessly changing good fluid out based off of a mialage interval or being hosed by a stealership when it doesn't need to be done!

I recently purchased the Kaiweets Brake Fluid Tester Pen for my shop, and it’s been a fantastic addition to my toolkit. As a mechanic, it’s essential to ensure brake fluid is safe and effective, and this tester makes the process quick and easy. The tester provides clear, precise readings of brake fluid moisture levels, with a simple 3-color backlight system that indicates whether the fluid is safe or needs to be replaced. The data hold function is a great feature, allowing me to easily show the customer the exact reading. It’s also calibrated for DOT3, DOT4, and DOT5.1 fluids, which is perfect for the variety of vehicles I work on. The corrosion-resistant probe is durable, and I love the buzzer alarm that alerts me when the moisture level exceeds safe limits. This tool has saved me time, increased accuracy, and improved the quality of service I provide to my customers. Highly recommend it for any mechanic looking for a reliable brake fluid tester

I'm big on maintenance on my vehicles, but a lot of the services that mechanics or quick oil change places try to sell you just aren't needed, at least at the intervals they're often recommended. Fuel injector service? Ridiculous, put a can of SeaFoam in your tank and fill up with premium the next time you're going to be on the freeway for an hour- injectors cleaned. That brings me to brake fluid- I HAVE seen brake fluid go bad but it's usually in a vehicle that is decades old, with a leak somewhere in the system. So I never knew if brake fluid REALLY needed to be flushed, or if it was just another money grab. Turns out that the moisture content can be checked, so I can actually know whether it needs to be flushed or not! And that's exactly where this meter enters the story: it can measure the moisture content in the meter and let you know if it's serviceable or if it needs changing. My 2020 Ram 1500? No moisture in the brake fluid, no need to bother. My 1979 C10? Yeah... definitely needs a flush. This is a great tool to have just to keep an eye on these things!