ITEM NAME:For GM EL-50448 Tpms Reset Tool Relearn Tool Tire Pressure Reset Meter Features: Compact design makes it lightweight and portable, easy to carry. Checking the pressure.After replacing a tire or wheel speed sensor. --The turn signal is lighted for 3 seconds and the horn beep sound twice to enter the learning mode. --Make the J-46079 or Diagnostic Tool EL-50448 antenna up against the valve core position & close to the rim of the tire sidewall.