Unique, dual-purpose design cleans and lubricates both the chamber and locking lug recesses of your M16 or AR-15 with one mop. Long, skinny portion reaches the chamber with individually-tied, cotton strands that do the work of a thousand tiny fingers. Short, large-diameter section cleans and lubricates locking lug recesses. Mfg: Brownells SPECS: Cotton or wool. 8-32 threads. Approximately 3" (7.6mm) long.