Stainless Steel Lock 4 Pack has four individual locks; one (1) Class III-IV receiver hitch lock (5/8" dia x 2 1/2" wide), one (1) coupler latch lock (1/4"dia x 1" span) and two (2) trailer door latch locks (7/16" dia x 5/8" span). All of the these locks are keyed the same for added convenience. *To add additional locks keyed the same, select (1) keyed the same upcharge per lock ordered. This is found under lock accessories category. This will notify us that you would like all of your locks keyed the same.