Provide your dog with access while keeping him contained with the Good Dog Exercise Pens. This pen allows step-through access with a convenient, sturdy-framed door, and accommodates a wire crate for added security and comfort (crates sold separately). Folding style play pen with hinged panel construction Folds Directly into Itself, Taking Up Minimal Space, Consuming Less Time in the Setup and Take-down Processes Easily Connects with Other Pens with Bolt Snaps Sizes 30"-36" are designed with a 3-point Locking Door. Size 24" are designed with a 2-point Locking Door. Why a Play Yard? Keeps Pets Away from Danger and Gives Them a "Yard" of Their Own No Exposed Screws, Wires or Pins to Injure Your Pet Provides Breathing Room and Visibility for Your Pet Offers an Easy Way to Manage Your Pet Regardless of Your Surroundings Easy to Transport Available in 24", 30" and 36" high panels.