This elegant marking gauge is really three tools in one — a wheel gauge, a pin gauge, and a cutting gauge.
The unique swiveling pin/blade chuck takes either a pin or a blade that locks in place (after extension is set) using a set screw in the end of the 115mm gauge stem. The cutting blade can be set for either right- or left-handed use. The opposite end of the stem is tapped to accept a 9.5mm diameter wheel cutter.
The fence and the internal portion of the locking collet are a single eccentric brass turning. The collet fingers have just enough stem friction to hold a projection setting while you lock it in place with a half turn of the knurled locking sleeve. The 25.4mm diameter fence is eccentric to maximize rub depth. A side benefit is that it also prevents the gauge from rolling off the workbench.
Comes complete with a dozen spare blades, two hardened steel pins, a wheel cutter and screw, and a hex key. Extra stems are available separately for those who prefer to switch heads as quickly as possible.