1) We monitor the pressure directly from tire valve. 2) Our light-weight sensor / transmitter is attached and locked onto the valve stem with a special key, proven reliable at ultra high speeds and fully sealed against all weather conditions. 3) The sensors transmit wirelessly to control panel. 4) We do not require anything to be installed inside the tire (fit on tire in seconds. 5) We use a reliable aerospace-developed membrane to trigger a visual and audible alarm when pressure drops below a threshold, set at the factory at 28PSI for passenger cars but can be specified by customers when ordered 6) Button batteries in the sensors last about 3 years, as they are not used unless the pressure threshold is crossed; The panel monitor will indicate when batteries need replacing on a particular tire 7) system was tested by the National Highway Traffic control 8) consists of 4-20 anti-theft pressure sensors attached to each valve stem to continuously monitor tire pressure and transmit coded signal to the control panel. Instrument when a loss of tire pressure is detected; A warning light and audible alarm on the dash display instrument shows which tire is losing pressure before the tire is damaged or becomes unsafe to drive on 9) Its anti-theft wheel sensors incorporate a pressure sensor and a microchip RF transmitter powered by 2 standard 3V li batteries, and are preset to customers Individual tire pressure requirements This system will give better performance from your vehicle, because you will know when to add more air to your tire, less wear on breaking system, use less fuel, less tire wear, better breaking, lower temp on wheel rims, but most of all best for saftey.