The self-centering feature of this jig puts the holes exactly in the center of the board.
The convenient positioning marks allow you to align it easily -board to board.
Two permanent holes guide 7/16" and 1/2" drill bits. Removable 1/4", 5/16" and 3/8" bushings are interchangeable in 2 other threaded holes in the guide.
Hardened guides for long life.
Accommodates wood up to 2" thick.