The Ultimate Exercise Pen (UXP Model) Offers:     A  Easy, one-hand door operation     B  Removable pin lets pen open up or be joined to other pens This Top of the Line Exercise Pen - Comes in long-lasting Black or Gold Zinc coating, the toughest on the market and a wise investment for serious professionals and pet enthusiasts Folds directly into itself, taking up minimal space, consuming less time in the set-up and take-down processes Has a removable drop pin which allows pen to be easily joined with other pens or to your crate for extra play space Offers standard locking door on all sizes Has an easy carry handle for transporting All Precision Pet Products exercise pens have eight 2'-wide panels, solid steel wire construction and long lasting finish.