Designed for a unique combination of solid work support in a small and maneuverable size, the MicroBlock has a self-centering jaw system made for stone setting, small engravings, and other precision work. The internal rotational brake system lets the user choose the amount of rotational resistance from free to locked. Its low profile is suited for microscope work. Includes 4 pins, 2 wrenches, 6 screws, plastic base, 1 plastic hex key, and Thermo-Loc Sample Kit. Block Weight: 4 lbs. (1.8 kg) Ball Diameter: 3.1" (80 mm) Jaw Width: 1.8" (46 mm) Jaw Height: 0.87" (22 mm) Max. Opening: 2" (50 mm) With a variety of pins that fit the upper jaw plates of every GRS Block, users can now instantly solve workholding problems and start working sooner. Includes 4 one-half Thermo-Loc sticks, 8 small pins, 4 flat square pins, 2 rectangular inset-curve pins, 4 thick round inset pins, 8 rubber-coated pins, and 2 leather-faced ring clamp pins in molded base.