An Ultralight Locking Carabiner from Camp that will serve many of your lightweight multi-pitch and high alpine needs.  The lightest locker Camp makes, and it is still a full-size standard size D-shaped carabiner.  Keylock style SphereLock gate closure helps prevent snagging and has a slim nose profile. Use these carabiners in conjunction with personal anchors, on the first piece of gear when leading a pitch, when building belay stations on multi-pitch alpine climbs, for crevasse rescue systems, and for many other uses.  Large enough to accommodate a clove hitch.  If you do a lot of different types of climbing, then you quickly learn how many different purposes that these will serve, and how many ways a few of these in your kit will help to protect you.  The "keylock" style gate closure has become one of the most popular industry standard designs because it prevents the carabiner from snagging when clipping on and off of slings, gear, ropes, and harnesses.