This 2-1/4" standard dial indicator gauge is for K&L Supply Co. indicator arm, 910-723, which mounts to the Three-in One truing stand, 910-720, Each Sold Separately Gauge reads 0" - 2-1/4" range in 001" increments Use it to build and true spoke wheels Check run out on crankshaft and fork tubes Balance spoke and mag wheels as well as axles