I got a hammock a few years back that came with steel 'biners for attachment to the tree straps. Replacing them with these lightweight mini-biners saves almost a half-pound in my pack. I also use one to hang my pack (with a pack cover) at night from a paracord wrapped around a tree, to keep the pack off the ground and out of my tent.
This review was written in the old system and had content requirements that are different than reviews written today.