Shimano CJ-7S40 is a cassette joint designed for use with Inter-7 hubs and coaster brakes. It allows for easy installation and removal of sprockets, ranging from 16T to 22T, without the need for special tools. The cassette joint is secured to the hub using a cassette joint fixing ring, which ensures a reliable connection. It is recommended to align the yellow marks on the cassette joint pulley and bracket with the corresponding marks on the hub body and bracket during installation. The CJ-7S40 is a durable and efficient component, suitable for various cycling applications.