The SPM55 series is specially designed for harsh industrial environment applications. It is a precise and accurate cursor control device, which operates at all angles and requires no cleaning. The touchpad uses the Field Distortion Technology to sense the presence of your finger. This device is not pressure sensitive, a light touch is sufficient, tracking your fingertip precisely. A light tap on the surface activates your selection. To drag and drop, just tap twice and hold your finger down on the second tap. Drag the item wherever you want, then lift your finger to drop. To double-click just tap twice. As alternative to the here above described operation you can use the separate buttons. Carrier plates and housing are metal (aluminum and steel). The units can be directly connected to a PS/2 port or to an USB port.