Life Stage A.C.E. Double Door Crate 24" x 18" x 19" Intuitive Innovation from Midwest Homes for Pets. Life Stages ACE comes with the amenities of a traditional wire crate with the added convenience and security of the MAXLock Door System. The patent-pending MAXLock Door System enhances security by providing multiple lock points around the perimeter of the door. The locking handle allows you to easily and conveniently operate the door in one motion without kneeling or bending. Simply lift to unlock and swing the door open. As you close the door, just lift, position the door against the crate and lower it into the eyelet latches. Secure the handle in the down position to lock the door.