2"-6" x .0005" Powerhouse® Dial Bore Gauge This is something that every engine builder, whether a beginner or a seasoned pro, should own. A Dial Bore Gauge, once set with a micrometer, is used to determine size, straightness or taper on main, rod, or cylinder bores. Powerhouse offers two models to meet your needs. Their economically priced .0005" model is fine if you just want to check your machinists work. Their Central .0001" unit is designed with high precision and repeatability in mind. Their Central bore gauge features a 2-8" range and an extended reach handle which is perfect for reaching center main-bearing bores. Each kit is supplied with a fitted case that also keeps all of the anvils and extensions organized.Powerhouse 2"-6" x .0005" Powerhouse® Dial Bore Gauge 205025 at low everyday prices. Be sure to check out all of our products from Powerhouse Products including Powerhouse Products Dial Indicators.