1. SMT components, LED back light effect, EL back light
2. EMI, RFI, or ESD shielding.

Membrane Switch
1,Flat and all embossed key type with either metal dome or mylar dome.
2,SMT components, LED back light effect, EL back light.
3,Jumper wire.
4,Selective texture with choices of clear, velvet and coloured display window.
5,EMI, RFI, or ESD shielding.
6,Tail termination - either male or female connectors.
7,Waterproof type (IP65).
8,Through -hole type.

Electrical
Maximum Circuit Rating   35V( DC)100mA 1W 
Contact Resistance  10Ω~500Ω (depending on trace length & material used).
Insulation Resistance   100MΩ at 100V DC
Dielectric Withstand   250 V Rms (50~60 Hz 1 min.)
Contact Bounce   5ms
Life Expectancy Flat type    Five million colosures 
Mylar type    2 million colosures
Metal type    1 million colosures 
 
Mechanical
Actuation Force Flat type   60 to 300 g (2 to 10 oz)
actile type   180 to 400 g (6 to 14 oz)
Switch Stroke Flat type   0.1 to 0.5mm
Tactile type   0.6 to 1.5mm

Environmental
Operation Temperature Flat/Metal dome: -40 °C to +80 °C
Poly dome: -20 °C to +55 °C 
Storage Temperature Flat/Metal dome: -40 °C to +85 °C 
Poly dome: -40 °C to +60 °C
Humidity 40 °C , 90% ~ 95% for 240 hours