Savi-Socket is the newest revolution for removing Hi-Lok® threaded collars. It is the first socket to utilize a conical/tapered shape with helical teeth to remove collars. This design firmly draws the socket onto the collar, gripping and removing the collar with minimal effort and wear on the tool. A gentle rocking action of the wrench while the collar is still on the threads releases the collar. This design prevents the socket from being used to install or tighten collars after the hex is broken off. This is a starter set that contains Savi-Sockets for 75-85 percent of the Hi-Lok® collars typically encountered in routine aircraft maintenance, including the most frequently encountered collars: The HL70 and the HL79 series red collars.