Ping-pong partitions, also known as table tennis partitions, are a type of netting used to separate two ping-pong tables. The netting is usually made of nylon or polyester and is designed to be lightweight and durable. The netting is typically attached to the table with clips or hooks and can be adjusted to different heights. The netting is also designed to be easily removable for storage or transport. The term 'ping-pong partitions' is derived from the fact that the netting is used to divide two ping-pong tables. The four letter solution to this crossword is NETS.