This 24kn Aluminum Screwgate Carabiner features a locking screw intended to prevent open-gate failure. The carabiner has an outside length of 4.5" and an inside length of 3.5". This is typically called a 1/2" carabiner. The carabiner has a nice oval shape that prevents ropes from chaffing and allows for easy clipping of ropes, knots and other climbing gear. Made from aircraft grade 7075 aluminum allow.This carabiner is not rated for lifting or climbing.