The Replacement QRBP is short for Quick Removable Breech Plug, this breech plug will only work on a 209 primer ignition Wolf, Optima,& Accura V2 rifles after it has been fitted to the barrel. This can easily be done with the QRBP fitting tool, that comes with the QRBP as well as simple step by step instructions. Each QRBP that comes equipped on 2010 CVA Wolf, Optima,& Accura V2 rifles is fitted to that particular barrel that it came with. This is why it is so easy to install and remove. Once the QRBP is properly installed no tools are required for installing or removing QRBP. This QRBP will NOT work in the CVA Apex Muzzleloader or any other muzzleloader that was not originally set up for QRBP.