Upgrade Games Maze Ball Toy 4 Layers It has one layer more than most track balls. The more levels and balls, the more fun the cat has. Detachable design: it can be detached, easy to install and clean. Multiple ways to play, not boring There is a hole at the top. You can insert a Tail Mouse and lose weight while playing with the cat. Such ways of playing can bring more fun to the cat! Smooth corners and non-slip floor We use safe, non-toxic and environmentally friendly PP polypropylene resin, which is odorless, wear-resistant and has a good impact resistance. The corners are smooth and burr-free. Cats can play safely! There are 4 pieces of non-slip mats on the bottom, more fixed to prevent pets from moving around when playing.