... " truck reversing aids system 2,Display the distance on the screen 3,alarm by English speech 4,two way video input Features & Functions ... ,60°Cwork temperature-30°C---+80°CAlarm typeSpeaker (English speech)alarm volume65dBSpeech report2.0m,1.5m,1.2m,1.0m,9 ... test3.Shockproof test4.Aging testProduct certificate: CE & FCCAfter- sale service: one year warranty English alarm truck reversing aids system