Assures accurate line up of dowel holes in furniture and carpentry. Jig is transparent, making layout simpler. See-through reference lines allow for lining up the jig perfectly. Holes are spaced 3/4" on center. Precise center line for the joint, plus center lines for 2 dowls. Hardened steel drill guide is 3/4" thick, perfect for 3/4" face frames. Includes convenient hanging hole. Measures 2" x 4-1/2".