The Park Tool DC-1 Digital Caliper is an essential tool for precision measurement in any bike shop. With a range of 150 mm (6 inches) and the ability to measure external, internal, depth, and stepped dimensions, it provides versatility for various components like seat posts and bearings. The large LCD screen ensures easy readability, while its accuracy of /- 0.02 mm and repeatability of /- 0.01 mm make it reliable for detailed work. The DC-1 supports measurements in metric, decimal inches, and fractional inches, making it a must-have for any cycling enthusiast or professional mechanic.