This Harmony XB4, double head has 1 green and 1 red button, operates with a spring return / impulse mechanism. It is marked with "I" and "O"symbols. This double head provides a versatile 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 clearly distinguishable visually at a distance thanks to clear colors and by touch due to flush elements, minimizing errors in machine control. 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. Its wide range of operating temperatures from -40C to 70C allows versatility in usage of product.