Grips small workpieces for precise drilling on the tabletop. Horizontal and vertical v grooves for small round pieces. Slots in base for mounting to workbench. (Mounting hardware included: 2 each of bolts, washers and wing nuts. The 7/8″ long bolts can be tightened with a screwdriver. Accepts #8 screws.) 4-1/4″ long x 2-3/8″ wide x 1-1/2″ high. Jaw width 1-1/4″. Jaw height 1/2″. Jaw capacity 1-1/2″. Mounting slots 11/64″ x 1-7/8″.