I have this Richbrook tyre pressure gauage as a keyring on my car keys and find it useful to have to hand. Obviously it can be useful to regularly check tyre pressures and this device allows that in a simple manner. The display shows PSI and BAR and has a range of between 5 and 99 PSI and between 0.4 and 6.8 BAR. The device is said to be accurate to within 1% and I believe that this is sufficient for monitoring my tyre pressures.
Keeping tyre pressures at the recommended level is important for a number of reasons, mainly for fuel economy and effectiveness of tyres for grip and under braking. The blue LCD display is bright and clear and there is also a white LED torch built in. The keyring has a rubber finish to it and the large clip helps with detaching the gauge for using it without your keys attached. Unlike a lot of products these days this one comes with batteries supplied and it comes in a presentable velvet-effect storage bag.
This tyre pressure gauage is small enough to have attached to my keys without having to carry a bulky device around with me. I check tyre pressures regularly and it can often save me money by not having to check all pressures at the garage when I am using the air on the forecourt. A worthwhile purchase for under a tenner.