The Bore Tech Proof Positive Bore Stix feature a proprietary alloy ferrule which eliminates any false indication of copper fouling in your bore. This paired with a new chemically resistant coating make the Proof Positive rods some of the finest available. Proof Positive Bore Stix feature caliber-specific steel cores with a cushioned ball bearing handle, which effortlessly follows your barrel rifling. The ergonomic, cushioned handle prevents any damage to your rifle stock. Proof Positive Jags sold separately. Here’s a list of Proof Positive Bore Stix features: - Proprietary alloy and secondary treatment process eliminates false copper reading - As soft and safe as brass with exceptional strength to prevent damage during use - Female ended ferrule is machined to provide an edge-free transition between rod and Proof Positive Jag. Eliminates the need for adaptors. - Highly advanced rod coating that provides anti-wear characteristics and prevents debris from embedding - Ergonomic, cushioned handle with an unparalleled ball bearing system. All .17 & .20 caliber rods use 5-40 threads. All others are 8-32.