Simple installation either through two mounting bolts on the top of the leg fixing bracket or via welding a bracket to the chassis / outrigger. The leg is held in a horizontal stowed position. To release, pull leg from locating notch and allow inner telescopic leg to extend by placing toe on release flange. Lock in place using tommy bar supplied. To release, apply pressure with toe on flange then raise back to stowed position. Both sizes of Camper jacks are sold as pairs. Mounting bracket 10cm x 5cm.