This Harmony XB4, black head with key (key no.421E) for key selector switch has 3 positions, operates with stay-put mechanism with key withdrawal on center position. This head with key provides a versatile interface for controlling your machines. It is easily installed and replaced on compatible complete key selector switch units to provide a secure manner for authorized staff to switch between process or machine operating modes. It is impact resistant, dust resistant, water resistant and vibration resistant thanks to its IP66. It has a metal bezel, this makes it Ideal for applications requiring high impact and vibration resistance. It is designed to fit in a standard 22mm cutout, ensuring compatibility when installing in pre-existing machinery. Secure machine and system operation with a key, only available to authorized operators. Its wide range of operating temperatures from -40C to 70C allows versatility in usage of product. Key removal allowed in only one of the positions, allowing for advanced interlocking between various parts of a machine or process, while limiting human errors.