TireMinder TMG400C Tire Pressure Monitoring System 4pk For RVs and Moderate Industrial Use, Pressure Range 0-145 psi Monitors up to 22 wheels, Monitors and transmits even when stopped or parked Accurate to within 2.7% , Visual & Audible Pressure loss warnings (user programmable) Temperature alarm if temperature rises above 167f/75c Replaceable CR1632 batteries (minimum 1 year life expectancy)