ARKSEN Precision Telescoping Gage, 1/16" - 6" Range T-Bore, 6-piece w/Pouch FREE Vinyl Pouch Points Are Hardened Tool Steel And Precision Ground In The End Measuring Radius Spring Loaded With Locking Knurled Knob Get Exact Sizes Of Holes, Slots, Bores, Or Recesses Double Action Design (Self-Centering) For Quick Checking Of Inside Measurements