Hopkins 38100VA Towing Solutions Tire Pressure Monitor System Monitors air pressure in real-time on up to 24 different tires at once (includes monitors for 6 tires) Four programmable memory positions means no need to reprogram each time you drive and/or tow a different vehicle or trailer; just save different vehicle combinations for recall at the push of a button Compact receiver unit provides easy to understand audible and visual alerts when tire pressure drops to unsafe levels Installs quickly Compatible with automotive and trailer tires with an operational pressure range of 10 to 150 PSI