This patented design helps speed up house training and eliminates messes caused by dogs missing the pad. The On Target Trainerhelps to keep a dog centered on the pad and properly positioned for perfect aim. The pad holder tray features built in clamps, which keep any standard size potty pad firmly in place and secure from playful puppies or slippery floors and carpets. Made with durable plastic for easy care and lifetime use, the unit snaps securely together in seconds. Tray size measures 22.75″L x 22″W x 1.5″H with 7″ high removable walls. Pads sold separately.