Three precision ground magnetic contact surfaces (plus V-step). Powerful, permanent magnetic base holds firmly to steel or iron surfaces - horizontally, vertically, upside-down. The swivel post assembly on these holders provides universal adjustment in both horizontal and vertical planes.
Magnetic Base with Swivel Post Assembly. The Starrett 657A Magnetic Base Indicator Holder includes a swivel post assembly that provides universal adjustment in both horizontal and vertical planes. Available with inch or millimeter Starrett Dial Test or Back-Plunger Indicators, they save time in shop set-up and other inspection jobs. Magnetic Base with Swivel Post Assembly.