Materials and Rockers

Rockers and materials are semantically related. In some cases you can replace term "Rockers" with "Materials", this words are similar.

Rockers noun - Originally a British youth subculture that evolved out of the teddy boys in the 1960s; wore black leather jackets and jeans and boots; had greased hair and rode motorcycles and listened to rock'n'roll; were largely unskilled manual laborers.

Materials and rockers are semantically related. Sometimes you can use "Materials" instead an adjective "Rockers".