Security Boss 4-Sided Exterior Kennel DoorDescription Security Boss 4 Sided Exterior Professional Kennel Door Custom Made Energy Efficient Kennel Dog Door Stop Energy Loss The 4 Sided Exterior Dog Kennel Door is an exterior kennel door model that features a heavy duty bi directional hinge connection to the flexible vinyl flap. This hinge also uses weather stripping that protects the hinge from drafts and energy loss. These doors are popular among kennel operators that have high energy dogs.