This Harmony XB5, flush red button head operates with a spring return mechanism. It is marked with a "O" symbol. This button head provides an ergonomic interface for controlling your machines. It is easily installed and replaced on compatible complete push-button units and contact blocks via snap-fit assembly. It is impact resistant, dust resistant, water resistant and vibration resistant thanks to its IP66 / IP67 / IP69 / IP69K. It has a plastic bezel, this makes it ideal for applications requiring good resistance to chemical agents and/or double electrical insulation. It is designed to fit in a standard 22mm cutout, ensuring compatibility when installing in pre-existing machinery. Its wide range of operating temperatures from -40C to 70C allows versatility in usage of product.