Hoppe's Boresnake Viper .308 - .30 Caliber Rifle, Clam E/F Washable and reusable quickest 3 step bore shine Brass weight on the pull cord Cone shaped bore guide on the leading end The world's quickest three-step bore shine 50% more brush cleaning power than the original BoreSnake Coneshaped bore guide for quicker alignment Designated lubrication zone on the handle; brass weight on the pull cord is stamped with size Patented one-piece design; machine washable