A large carabiner can come in handy in many places. This one's shape and size means it's useful for belaying and rappelling with the Munter hitch with single or double ropes, anchoring multiple ropes and slings and keeping the belay station organized.

Pear shape facilitates use with the Munter hitch for single or double ropes.
Large shape and gate opening can fit multiple slings and ropes.
Keylock system.