Dasqua 4 piece .125-.500" small hole full ball gage set. Measuring ranges are 3.5mm, 5-7.5mm, 7.5-10mm and 10-13mm. Use these gages with an outside micrometer to measure inside bore diameters. Gage surface is fully hardened to ensure long tool life. Extra long for gaging deep and shallow holes, slots and similar workpieces. Satin chrome finish. Full ball.