The convertible floor tray is specifically designed for use indoors with the Richell 4/6-panel rectangular playpen or the 4/6-panel convertible elite pet gate. Richell Convertible Indoor/Outdoor 4-Panel Pet Playpen: * Recommended for small to large dogs 6 to 88 lbs. * 1-1/4" space between plastic slats * Durable blow-molded plastic construction * Specially designed hook arrows allow the playpen to be used indoors or outside * Lockable gate door provides extra pet security and easy mobility * Panel designed to allow for various size configurations * Indoor/Outdoor Pet Pen is easy to assemble; easy to clean