Avid Gun Boss Pro Universal Cleaning Kit PUTTING THE SMACKDOWN ON OTHER CLEANING KITS. The verdict is in: Most kits feature flimsy, spill-prone trays. That's why Avid made Gun Boss Pro. A sturdy, sleek, secure tool case loaded with high-quality brass rods and a new, innovative multi-function rod handle. Components and compartments are labeled making organization a breeze and the patent-pending kickstand case keeps everything within easy reach. Gun Boss Pro is the best way to keep every piece in place. Case closed. Fits .22 - .45 cal., 20 ga. & 12 ga.