Set of 6, Models HV072, HV073, HV074, HV075, HV076, HV077 in caseSETSSELF-CENTERING WITH TWO TELESCOPING ARMS; 5/16-6" (8-150 mm); Handles are rigidly attached to the contact plungers and are automatically self-centering. Constant spring tension gives uniform contact pressure and both plungers are easily locked at any desired setting.