LB1 High Performance 6 Pc Machinist Telescope Gage Gauge Tool Measuring Stainless Steel Hand Tool New(5/16" To 6" Range) 6 Pc Machinist Telescope Gage Gauge Tool Measuring Stainless Steel Hand Tool New(5/16" To 6" Range) Professional Precision Tool Set! Easily Adjust with Twist Lock. Spherical Measuring Faces are Hardened. Polished Satin Chrome Finish, with Case Included. Range: 5/16 to 6 (8mm  150mm).