The BESSEY solid surface seaming tool's twin vacuum cups secure the clamp to any smooth, non-porous material such as solid surface, SSV laminate, polished marble & granite and eliminates the need for glue blocks. The PS55's 120 mm (4-3/4 Inch) diameter suction cups create 48 pounds of clamping force, and are made from rugged high-pressure aluminum alloy with the highest quality rubber diaphragm. The large diameter ACME type lead screw smoothly pulls the two work pieces together. Come with the ergonomic shaped wood handle. A great time saver. BESSEY. Simply better.