BLAKE Co-ax Indicator Set - Model: CX-1 Delivers quick, accurate centering in boring and milling set-ups. Face indicator remains in fixed position while the machine spindle rotates. Measuring range: .250" axis offset Locating accuracy: to within .0002" of true center Length: 6-7/8". Shank: 3/8" diameter x 7/8" long. Feeler ball: 1/8" diameter