Analogue tyre gauge The Ring Analogue Tyre Gauge has measurements in psi and bar, and a range from 0-120psi and 0-8bar. These analogue tyre pressure gauges are easy to use and are accurate to +/-2psi. By regularly checking your tyre pressures (at least once a month) and checking that your tyres are at the correct pressure you will prolong your tyre life. Correctly inflated tyres can also save you fuel and lower your CO2 emissions. Main Features: The Depth Gauge is easy to use Accurate to +/-2psi. Specification: Tyre gauge range - 0-120 psi / 0 - 8 BAR.. Accuracy - +/- 2 psi. Tread depth range - 0 - 25mm