Black Diamond's Big Air XP Package pairs a tube-style belay device with a burly locking carabiner, so it's ready to give your friend a catch. The ATC XP features internal grooves to boost friction, helping to relieve some pressure from our brake hand, and two slots for use with twin and half ropes. The pear-shaped 'biner's rounded construction and large rope-bearing surface make for smooth slack pays and lowers, while the screw-lock gate boosts security through it all.