A really nice, large, locking belay carabiner at a very reasonable price. Keylock nose means less snagging, screwgate lock mechanism resists clogging, big size useful especially when wearing an Alpine Bod harness, or if you insist on clipping the biner through both the leg loops and waistbelt, rather than using the belay loop. (Which you should never do).

(And no, the Black is not smaller than the Grey.)