Bore Tech Proof-Positive Patch Loop 22-45 Caliber. It features a proprietary alloy and secondary treatment process making it 100 percent brass free and 100 percent barrel safe. This alloy is as soft as brass but boasts an exceptional tensile strength to prevent bending and snapping under the force of a tight patch. Specifications for Bore Tech BTAL-100-00 Proof-Positive Patch Loop 22-45 Caliber: Manufacturer: Bore Tech Fabric/Material: Aolly Quantity: 1 Length: 2.19 in Projectile Caliber: .22 Caliber Gun Type: Rifle The Bore Tech BTAL-100-00 Proof-Positive Patch Loop 22-45 Caliber is a quality addition to the Bore Tech lineup. For more great deals on Gun Cleaning by Bore Tech please browse our Bore Tech Gun Cleaning Kits page.