The Proximity Switch detects objects without contact and without moving parts. Its rugged molding housing protects the transducer against dust,dirt and oil found in an industrial environment and can be washed down without harm. The 816-SS is mounted on a 200lb stay put magnet for instant secure placement anywhere on the machine. The proximity switch comes complete with a 10 foot power cord. The 816 sensor switch option is designed for electrically activated systems.