Here's a COMPLETE SYSTEM for FIELD MORTISING Perfect Lock Bores and Latches on Wood Doors for CYLINDRICAL LOCKS. Just SLIDE it onto Door and CLAMP IT !! Then Use the 2-1/8" Bit to Bore Holes from BOTH SIDES. Use 1" BIT to BORE LATCH Hole AND THE 5/16" BIT TO DRILL THOSE 2 SMALL HOLES IF REQUIRED. The COMPLETE SYSTEM includes a LOCK BORING JIG FOR EACH BACKSET ( 2-3/8" and 2-3/4 ").... ALL BORING BITS..ONE EACH ( 2-1/8", 1.0" AND 5/16")....(1) ROUTER BIT (1) CORNER CHISEL.... (2) CLAMPS and CARRYING BAG ... Your Lock Prep WiLL look like FACTORY in a SNAP !! Professional Crafted Set for The Door and Hardware PROFESSIONAL !! Of COURSE it's MADE in the USA !!! Look at the Pictures to see how everything works !!