This Harmony XB5 emergency stop / shutdown 40mm mushroom red button head operates with a latched key release (key no.458A) mechanism.It provides an ergonomic interface for controlling your machines.It is easily installed on compatible complete emergency stop and switching off push buttons.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.It makes it ideal for operation in harsh environments.