Swinging Single cylinder - Marks Hardware Gate Locks. Reversible Swinging Gate Locks With Patented No Fallout Feature. 1 mortise cylinders included. Case, cast aluminum 3-5/8 x 6-1/4 x 1. Groove:1/ 2 wide x 3/16 deep,all sides for wire gate insertion. Reversible, Now the handing can be reversed in the field. Parts will not fall out when cover is removed. Cylinders included.