SPI Telescoping Hole Gage Set Plunger on gage expands in hole to be measured, locks in place, and remove gage from hole. Final hole size is obtained by measuring over contacts with a micrometer. Features include... 6 gages in fitted carrying case 5/16" - 6" Measuring Range Contact points are of hardened and ground precision tool steel. Satin Chrome Finish Supplied in vinyl pouch. Gages included in set... 5/16" - 1/2" 1/2" - 3/4" 3/4" - 1-1/4" 1-1/4" - 2-1/8" 2-1/8" - 3-1/2" 3-1/2" - 6"