The Powermaster Dry Lining Box 1G 35Mm is designed to accommodate one electrical device, such as a switch or socket. The 35mm measurement indicates the depth of the box, which is the distance between the front face of the box and the back of the box. This dry lining box is installed by cutting a hole in the wall where the electrical component is to be mounted and then inserting the box into the hole. The box is then secured in place using screws or clips that are attached to the back of the box and fastened to the wall. Dry lining boxes are commonly used in residential and commercial construction as a means of concealing electrical wiring and devices within walls for a cleaner and more streamlined appearance. The box is suitable for a variety of applications and is available in a grey color.