Our standard wheel marking gauge is a great workhorse and excellent value. Its popularity led to the development of a second model that incorporates a micro-adjust feature. It is similar to our standard wheel marking gauge with an anodized aluminum body, brass face, stainless-steel rod and internal O-ring to keep a constant light friction force on the rod. It differs in that the body is slightly longer and is fitted with a two-stage collet that allows micro-adjustment of the cutting wheel. The collet has a fine-pitch thread; one revolution advances or retracts the wheel 1/32", a half turn 1/64", a quarter turn 1/128", etc. The knurled thumbscrew then locks the setting.