Leg type dial calipers used for measuring diameters and narrow grooves in hard to reach places. Internal specifications: range: 55 - 75mm, graduation: 0.01mm, groove depth: 8mm, groove width: 3mm, maximum reach: 100mm. External specifications: range: 0 - 20mm, graduation: 0.01mm, groove depth: 6mm, groove width: 3mm, throat depth: 60mm.