The Mighty Mini is a general-purpose clamp that does the work of a 1", 2", or 3" C-Clamp, but nine times faster. Rail size: 19/32" x 3/16"; throat depth: 2"; capacity: 4"; and nominal clamping pressure: 330 lbs. The clamp is part of Bessey's Tradesman line that features a patented nonslip locking system, greater holding power than any other clutch-style clamp, corrugated cast jaws, high quality galvanized profiled rail, and glue-resistant non-marring plastic caps.