SHMZKSHMZK 4PCS Car Tire Pressure Monitor Valve Stem Caps, 3 Colors Alarm Tire Indicator Valve Stem Leak Monitor, 2.4Bar 36PSI Tire Pressure Caps for Car Truck Bicycle Motorcycle (Silver)

Previously purchased 2 four packs of these valve covers for my Harley and Ebikes. Great and fast way to see the air pressure level in each tire without getting out gauges and getting on my knees! Purchased this set for a friend to use on his Goldwing trike. Much cheaper than electronic indicators and quick/simple to install.

They don't work to well, some of them caused my tire to leak

Garbage caps break off and leave you with a flat tire ruined one of mine do not use

These did not work out. They were fine for about 2 weeks. Then the top broke off one of them or something. Caused a flat tire. I was relieved when I figured out this was the cause

I purchased these because one of my tires have had a pesky leak for a long time. I put them on all four tires at 35 psi and the indicator showed Green. I slowly removed air and took measurements every 2 psi increments down to 25 psi. The Yellow indicator never showed, but I did get a Red indicator. The point of the TPMS is to see when the pressure drops incrementally, so I could add air at around 28-30 psi without having to take a physical measurement. For this reason, I give the item a 1-star rating because this is a safety issue. I did receive 2-sets of 4. I found that one of the sets had one cap that did not work.