Membrane keyboards are programmable keyboards with numerous pressure sensitive switches located under a soft surface. A plastic layer with small holes divides the membranes. Since the membranes are on the inner sides of the layers, the construction is protected quite good and are resistant to dirt, dust and water. Membrane switches and keypad services are important in different industries. These include aircraft or aerospace, automotive, building controls, communications and electronics, financial services, manufacturing or automation, medical, retail, and security and identification, Tactile Keyboards, designed to carry low voltage signals, Non-tactile, Silicon rubber keypad etc. They are available with Bakelite switches, LED indicators, EMI / RFI protection, ESD protection, and embossed switches, and with low temperature or high temperature with contact resistance of 100 Ohms and a break down voltage of 200 Volts. They often fabricated with materials like polyester, polycarbonate, rubber or silicone and metal.