Pre-programmed at the factory with exact OE protocol, so it's ready to be installed and OE-relearned out of the box. Designed and manufactured to meet or exceed OE performance in compliance with all SAE2657 specifications. Undergoes extensive testing-including operational temperature, thermal shock, extreme temperature, humidity, frost, proof pressure, rapid deflation, contamination, salt fog, drop, centrifugal force vehicle speed, mechanical vibration tests-to ensure durab. Validated at independent lab during 168-hour on-vehicle live test. Military-grade lithium battery ensures maximum battery life and sensor performance. Low-power wakeup timer and periodic reset driven by Low-Frequency Output (LFO) maximizes shelf life, extends battery life, and maintains optimum performance levels. Z-axis or duel XY-axis accelerometers on IC chip ensure more precise readings on tire positions and rotational direction. External-crystal oscillator provides frequency stability and more accurate frequency ranges, ensuring more reliable communications between sensors and vehicle receivers.