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. We offer two models to meet your needs. Our economically priced .0005" model is fine if you just want to check your machinist’s work. Our Central .0001" unit is designed with high precision and repeatability in mind. Our 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.