The differences between our standard Deluxe models and our top of the line Professional crates has to do mainly with its heavy duty door construction. On any crate the door is consistantly the weakest point and "Houdini" dogs typically target this area in their attempt to escape. In the Professional series we have reenforced the door with extra bars, welds and bracing. As an added layer of security in the Professional series we have added a secondary locking plate to the door frame and to add extra value we also include a set of Heavy Duty Handles. Each door has a full length piano hinge and can be mounted to open left or right. The Professional line of aluminum dog boxes are designed to be the most secure and safest of the Zinger crates.