Switchgear units (or switchboards) and enclosures are components of electrical systems that are integral to one of its most important functions. Switchgear units can be installed indoors or outdoors. In either case, they must be sized correctly to ensure that they can accommodate multiple devices such as fuses/breakers, meters, overcurrent and residual current circuit breakers, and more. Depending on the installation location, a switchgear unit can be made of plastic or metal. Most often, the installation of the devices takes place by installing the switchgear components on a standard DIN rail. The most common version of these mounting rails is the 35mm wide one and is also called TS 35, TH 35, or DIN-3.