Residential door hinges spring -standard weight -steel full mortise -square corner -bright brass -4 inch by 4 inch. Automatically closes doors for use as an alternative to overhead mounted door closers in corridors, entrances, and stairways. Ratchet adjustment eliminates need for adjustment locking pin and allows for quick fine-tuning tension up or down with allen hex key. Use with anti-friction hinges for best performance. Pivot point designed to align with cb and fbb series anti-friction ball-bearing hinges. Conforms to ansi/bhma standard a156.17; meets nfpa80 standard for 3 hour fire rated doors minimum 2 per door required; uk fire approval for use on fd30 and fd60 doors. Products packaged with hex wrench. 4 inch x 4 inch for 1-3/4 inch thick up to 3 foot by 7 foot and weighing up to 50, 85, or 110 pounds.