The Ratchet hook and the 1mm and 2mm Micro Grip hooks areself-locking hooks. They have a patented mechanism which grips the cord or cable only in the downward direction. Hence, they can be easily slid up the hanging wire –just pull down on the hanging wire with one hand and push the hook up with the other hand.
The self-locking mechanism prevents the hook from sliding down the hanging wire on its own accord. Pinch the plunger top and the bottom of the hook together to slide the hook down the hanging wire.
To insert the hook onto the hanging wire you feed the wire into the hole on the plunger top of the hook. Then push the hanger through the hook body and out through the bottom of the hook.