The Robert Sorby double ended callipers are a must for every woodturners kit, whether they are creating bowls, goblets or spindles. The large rounded shape allows them to be fitted around the shape of a turned bowl to measure the thickness of the wall, even towards the bottom, or simply measuring the thickness of an easy to get to spindle. This 177mm (7Ó) version has a larger throat to cater those vessels with smaller openings.