Hubbell® Circuit-Lock® pin and sleeve mechanical interlocks are a revolutionary design that incorporates a disconnect switch and pin and sleeve receptacle in a compact non-metallic unit. These devices offer maximum safety by preventing users from mating or breaking a circuit under load - Hubbell® interlock mechanism detects the presence of a plug and prevents it from being removed when the switch is in the "ON" position. It features a high visibility red handle that can be locked in the OFF position to meet OSHA lockout tagout regulations. The enclosure door can be locked to prevent unauthorized access. The rugged, corrosion resistant type 4X PBT enclosure features adjustable mounting feet for flexible installation, while the receptacle's spring loaded cover with gasket is dust tight and provides a watertight seal when turned and locked. The patented Plug-Check™ mechanism detects the presence of the plug. It operates as a clutch to engage the handle with the switch and captures the plug. This action prevents the plug from being removed until the switch is turned OFF.