Taytools MGB Solid Brass Wheel Woodworking Precision Marking Cutting Gauge with Micro Adjust Head Marking/cutting gauges are indispensable when marking out precision jointery Solid brass 1.625 diameter micro adjust lockable head, knurled adjustment knob and tail Hardened 3/8 diameter round cutter easily slices across wood grain Cutter head retraces into countersink in head to protect when not in use 7" by 5/16" diameter hardened steel beam is grooved to prevent head rotating during adjustments