Cart Wheel Chock

My workplace is moving facilities and to do this a moving company has supplied us moving carts to load items onto to be shipped, however the casters on these carts do not lock and so when trying to load or cling wrap the carts, they have a tendency to travel of their own accord. The chocks are aimed at preventing this and have proven useful during our site move. The hold running through the back is so that rope may connect multiple chocks, for stowing purposes and also to prevent injury when removing the chocks- the rope can merely be pulled and fingers don't have to get rolled over.