The Vestil DR-LOCK Automatic Overhead Door Lock allows overhead doors to be locked in virtually any position. Overhead door lock automatically locks doors in the full up position or in the closed position. Designed to prevent the overhead door from slamming down on workers, products, and equipment. Overhead door lock bolts to any overhead door (installation hardware is not included). To release the lock simply pull on the included rope to disengage the spring-loaded locking latch. Overhead door lock comes with two reversible locking plates that may be mounted anywhere along door track. Lock is 6-1/2"W x 5" D x 3-15/16"H and weighs 3 LBS. Heavy-duty steel construction with yellow enamel finish.