4-1/2 in. x 4-1/2 in. Spring Hinge (3-Pack)Life Security Products 4 1 2 in. x 4 1 2 in. Spring Hinge in a U. S prime finish and functions as a full mortise single acting spring hinge. This hinge type is used where automatic self closing of a door is desired. With this hinge type there is no need for an additional door closer. The hinge is fully adjustable and the speed of which the door closes can be easily controlled by using the adjusting tool and tension pins which are included. Heavy duty