This Harmony XB4, Emergency stop 40mm mushroom red button head operates with a latched key-to-release (key no.455) mechanism.This emergency stop / shutdown button head, is easily combined with contact blocks and installed into standard 22mm diameter cut-outs and connected with simple screw-clamp connections.It is clearly distinguishable visually at a distance thanks to a clear color and 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.Secure machine and system operation with a key, only available to authorized operators.Its wide range of operating temperatures from -40°C to 70°C allows versatility in usage of product.