Soft 4x3 Keypad Matrix lets you quickly add controls to your electronics projects. It offers 0-9 numerals, standard star (*) and hash (#) symbols. 
 

Contact resistance of 500 Ω 
Insulation resistance 100M Ω 
Key Operating Force 150-200 N 
Rebound time 1 ms 
Life of 100 million times 
Operating Temperature 60 °C

The electronic characteristics 
Circuit Rating: 35V (DC), 100mA, 1W 
Contact resistance: 10Ω ~ 500Ω 
(Varies according to the lead lengths and differs from those of the material used) 
Insulation resistance: 100MΩ 100V 
Dielectric Strength: 250VRms (50 ~ 60Hz 1min) 
Electric shock jitter: <5ms 
Life span: tactile type: ≥ one million times