The keyboards are suitable for use in both explosive gas atmospheres in Zones 1 and 2 (Category 2G) and explosive dust atmospheres in Zones 21 and 22 (Category 2D). They have been certified by Dekra Exam in the types of protection Ex ia IIC T4 (gas) and Ex iaD T135°C (dust). The range of keyboards with EC-Type Examination Certificate includes keyboards for front or rear mounting, desk-top and console keypads. The Ex keyboard and the Ex mouse are connected via an associated interface. The interface [Ex ia] IIC is mounted in an enclosure that snaps on to a DIN rail and limits the energy. The interface shall be installed outside the hazardous area. Keyboards without mouse control only require one interface, while keyboards with additional trackball or mousepad require two interfaces. The built-in, desk-top or console keyboards feature a touch pad and, optionally, a trackball made of plastic or stainless steel. Connection to the PC is made via the PS2 interfaces.