5.56 mm (0.223 cal). Double duty cleaning system. Home & field cleaning combo. Bore boss for quick cleaning in the field. Professional kit for a complete clean at home. Expanded gun cleaning kit. All the tools you need to fully clean bore, action & chamber. Ergonomic t-handle. Phosphor bronze bore brush. Nylon bore brush. Bore mop. 25 bore patches. Bore patch jag and slotted tip. Every components is easily accessible. Butterfly style case lays flat when open. Molded case holds components in place. Accu-grip detailing pick. 2 - smart brushes. 4 -piece coated steel rod. Home & field professional gun cleaning kit. RealAvid.com. Made in China.