• Similar to the 229 Telescoping Gage with a slightly greater range and two telescoping contacts
• Handles are rigidly attached to the contact plungers and are automatically self-centering
• Constant spring tension gives uniform contact pressure
• Both plungers are easily locked at any desired setting

The Starrett 579 Telescoping Gage is used for determining the true size of holes, slots, and recesses up to 6" (150mm). The ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gage will enter. The tool must be slightly rocked in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn. The final hole size is obtained by measuring over the gage contacts with a micrometer. 5/16-1/2" (8-13mm) Range, 2 3/8" (60mm) Handle.