This Single Spindle Edge Clamp will increase the versatility of sliding bar clamps with rails up to 1/2" thick. It is part of Bessey's Tradesman line of clamps that features a patented nonslip locking system, greater holding power than any other clutch-style clamp, corrugated cast jaws, high quality galvanized profiled rail, coated oversized acme thread, large ergonomically shaped wood handle, and glue-resistant non-marring plastic caps..