Angled clamping screw on moveable jaw exerts downward force that keeps workpiece from lifting out of proper alignment. Precision ground on all surfaces. Jaws are 2 inches wide x 1 inch deep. Opens to 3-1/4 inches. Overall height 2-3/16 inches. Base plate is 6 inches long. Includes V-grooves for round workpieces and threaded hole for mounting stops and other fixtures. Includes 2 mounting blocks.