This is the same adjustable bar that comes standard on the Kreg Precision Mitre Gauge. This 3/8" tail x 3/4" (9.5 x 19mm) wide bar has six plugs along the 30" (762mm) length of the bar that adjust with a screwdriver to take up any play in the mitre slot. Mounting holes are located every 100mm along the length of the bar. Perfect for building workshop jigs and fixtures.