This ball pit is contained in a circular plastic container that is easily able to fold and remove at leisure. Once unfolded, it is large enough for my 10 year old autistic grandson and his 6 year old sister. He immediately was drawn to it and he got in through the trapped window and played for hours. It has plenty of meshed Windows all around the pit for the kids to see you and you to monitor them. It says it will need 400 balls, but I put in 500 and it could stand another 100 balls or so...but this ball pit is WONDERFUL, STURDY, and COLORFUL...great buy..