... adopt stainless steel keypad, which contact resistance≤30ohm,life cycle≥2 million,push force 160-200grams,defend grade is up to ... Good tightness , Denfend grade is IP67.2.4 Hook adopts magnetic induction switch, life cycle ≥500 thousand2.5 These electronic components of ... with srore ,memory,dial (Each number up to 16 )2.7 Easy for install and operateWeather-resistance telephone, Anit-Explosion ...