Membrane switch 1.Humidity:40C,90% -95%,240 hours 2.Contact bounce:5ms 3.life: more than 500 million times Membrane switch Specifications/Special Features:Material: matte PC (smooth), gloss PC + matte oil, gloss PC, PET, and PVCThickness: 0.05---1.0mmLED windows: transparent,translucent,matteEmbossed keys: no embossed keys and domes, domes without embossed keys, embossed keys without domes, ...