This Schneider Electric Harmony K adaptor plate is designed to be used with 22mm Cam Switch/Selector Switch. This adaptor plate is designed to meet most industrial and process control application thanks to a compact size, an easy integration with 16 millimeter and 22 millimeter diameter units and has several selection functions. Simple and modular design to allow for easy installation. Designed to fit in 16-22mm cutout, ensuring compatibility when installing in pre-existing machinery. Sturdy plastic body resistant (strength) to shocks and corrosion.