Self-tightening. Great for single-lip flanges and inside frame horns. Original wedge; cross-hatch tooth design; spring-loaded for easy opening. Throat clearance of 1 1/2" high (38 mm), 1 1/4" deep (32 mm). Gripping surface: 1 3/4" wide (45 mm), 1" deep (25 mm). Overall length: 9 1/2" (241 mm). Weight: 7 lbs. (3.18 kg). Capacity: 5 tons (4,536 kg).Mo-Clamp 0670 Baby Box™ Clamp