Abstract: A device for removably attaching carts or the like such as used in supermarkets is comprised of a casing fixed to the handle of a cart. The casing is equipped with a plunger wherein a coin may be inserted into a coin housing in the plunger to release a locking key. The locking key can be affixed by means of a chain to either the casing of a preceding cart or to any other suitable support. Insertion of the locking key into the casing will release the plunger to allow the user to again gain access to the previously inserted coin.