if you have ever gone rock climbing or seen rock climbing equipment, you have most likely seen a carabiner. These great hooks have a spring-loaded gate on them. The idea is that you the hook will only go one direction when capturing an object. The gate on the carabiner only opens in one direction; the robot navigates to the object and forces the carabineer hook onto or over the object, allowing the gate to open when hooking the object, but when the gate closes, it will not open in the opposite direction thus holding the object on the hook