Starrett S579GZ Telescopic Gauge Set, 4 Piece 8-54mmHandles are rigidly attached to the contact plungers and are automatically self centering. Constant spring tension provides uniform contact pressure and both plungers are easily locked at any desired setting. Range 8 13 mm (5 16 1 2 Inch) Handle 60 mm (2 3 8 Inch) Range 13 19 mm (1 2 3 4 Inch) Handle 60 mm (2 3 8 Inch) Range 19 32 mm (3 4 1 1 4 Inch) Handle 60 mm (2 3 8 Inch) Range 32 54 mm (1 1 4 2 1 8 Inch) Handle 60 mm (2 3 8 Inch)