Abstract: A single length, wire-formed latch is pivotally attached to the hook of the chain and is so configured as to blockingly span the mouth of the chain-receiving slot of the hook when the latch is in its closed position. By grasping opposite limbs of the latch disposed on opposite sides of the hook, the latch may be pulled back against the resistive tension in the limbs to open the slot and allow the ingress and egress of the chain. One illustrated embodiment utilizes a pair of spaced mounting holes in the hook body which receive corresponding inturned, free ends of the limbs, while a second embodiment utilizes a single mounting hole in the hook body to receive one of the free ends of the limbs, the other limb having its free end extending across and bearing against an exposed, offset fulcrum surface on the exterior of the hook body to resiliently stress the limbs when the latch is pulled back into its open position.