Starrett Valve Seat Run out gauge (used once)Check concentricity of valve seats precise to .001in. Use after grinding or cutting seats. Complete tool mounts on seat-grinding pilot. Place probe on seat and rotate pointer. Jeweled-bearing indicator reads plus or minus .050" with .001" precision. Three accessory pilots included 5.52 mm (.2173) 5.55 mm(.2187) 6.63 mm (.2610). $400.00. 916-316-08 two six