This unique product is the most versatile locking unit available. It will accommodate 7 different hole spacing patterns from 3 to 6-7/8 in. The 3-15/16 in hole spacing is designed for use with mortise lock installations using Adam Rite and W and F mortise locks. These holes are offset 1/8 in from that of the locking cylinder hole. The spacing allows locking unit to adapt to a variety of handle sets.