Get set-up for fast, repeatable drilling and cutting. The aluminum arm flips down when you need it and stays out of the way when you dont! Slides up and down any fence with a top-mounted T-track and locks down with a comfortable 1" diameter knob. 5/16" T-bolt fits both standard and Universal T-tracks.Also available: Rockler Flip Stop for 2-1/4" fences (31214).The Flip Stop measures 3/4" wide, 1/2" thick, and 3" high on the back or short side of the arm.