Noga has developed a unique fine adjustment mechanism which is placed on the magnetic base. This mechanism allows the hand to rest on the base rather than on the clamp of the indicator. Zero-setting becomes faster than with any other mechanism. Unique single direction Fine adjustment at base. Powerful ON/OFF magnetic base. Holds 3/8" and dovetail. Unique central locking mechanism with Noga designed spring loaded bearing. Five axis holder. Instant fixation in any position. Easy to set up into required position. Black finished Arms.