"Sunex 6in. long torque limiting extensions are made of flexible spring steel that stops turning when the required torque has been reached. Set contains most popular sizes and torque ratings in the automotive service industry. Torque limiting extensions often extend the life of thin wall impact sockets by limiting torque to the required rating. Drive in. 1/2, Extension Length in. 6, Material Type Spring steel torque limiting, Pieces qty. 5. Includes 65 ft.-lb., 80 ft.-lb., 100 ft.-lb., 120 ft.-lb. and 140 ft.-lb. rated extensions Blow-molded case"