Locking mechanism helps leave both hands free when clamping, helping to eliminate squeezing action and general hand fatigue when manipulating. Tip of release lever projects at end of handle for a quick, no-pinch, powerful release especially when tools are firmly locked. Spring loaded release lever is out of the way when handling. Drop forged jaws and rugged tooth profile for durability and toughness. Holes in mobile jaw are drilled and not press punched to ensure they are cylindrical to ensure maximum bearing with rivets. (Punched holes tend give poor bearing.) Large diameter of rivets to help permit secure joints adding to the durability and robustness of the tools. Piano wire spring for smooth and efficient jaw opening.