Each circuit contains a ball that runs through the track like a roller coaster. This hide-and-seek design tickles the cats hunting instincts and will keep you playing for hours of chasing and touching the ball. It is very easy to assemble the circuit. Align each connection and press it until it clicks. To remove, press the protrusions on both ends and pull them out. Cover can be removed as well. Easy to Clean - Parts can be easily removed. Clean the stains with soap. Do not use chemicals or solvents. Rinse thoroughly