... EnvironmentOperational voltage:≤380V AC or ≤220V DCAmbient air temperature -25°c~ +40°cAltitude: ≤2000mRelative air humidity: ≤90%Pollution degree: class 3Protection degree ... 5.Other modles for reference:flush head,mashroom head,spring return,turn release,turn to stay up, ... dobble button,with key ... reset,convex,waterproof... ip66 waterproof pushbutton switch XB4-BP21,spring return