Whoopi Sling Knob

This is a knob that you can put on a rope and then tension the rope. When you're done, you spin the knob and pull it off.

The rope I used here is some 1/8" Amsteel that I turned into a whoopi sling. It has a nice method for tensioning but I didn't end up using it for my hunting gear as it was a little too unwieldy.