This Harmony XB4, 40mm mushroom black button head operates with a spring return mechanism. This 40mm mushroom shaped push button head is ideal for situations where quick actions are required for a process or machine to function correctly or where operator movements require maximum ergonomy. It is easily combined with Harmony range of contact blocks to perform a large variety of control functions. It is clearly distinguishable visually at a distance thanks to a prominent 40mm mushroom shape. It is impact resistant, dust resistant, water resistant and vibration resistant thanks to its IP66 / IP67 / IP69 / IP69K. 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. Its wide range of operating temperatures from -40C to 70C allows versatility in usage of product.