Kleen-Bore Mop20 Bore Mop 20,28 Gauge Shotgun Cotton #5/16-27 Thread This Bore Mop By Kleen-Bore Was Developed To Be An Ideal Tool For Helping Achieve Proper Maintenance Of Your Firearm. Made Of 100% Cotton, The Mop provides The Best Absorbency And Is Ideal For applying solvents/oils To a fouled Bore Or applying Your Favorite Rust Preventative/Oil after The Cleaning Process Is Complete. Quantity: 1 Bristle Type: Cotton Thread Pattern: 5/16-27