The hardened steel wheel cuts wood fibers rather than tears them, which leaves a clean mark, even on cross grain. The wheel's single-sided bevel also forces the gauge face against the stock, maintaining accuracy. The cutting edge of the wheel is at the extreme end of the shaft, which is useful for transferring dimensions such as tenon shoulder or mortise depth. The wheel retracts into the face of the gauge for storage.
The micro-adjust gauge is available with either an unmarked rod or a rod graduated to 6" in 16ths.