100% double knapped cotton patches are saturated with T17â Bore Cleaner. Specially formulated to clean and neutralize the corrosive effects of black powder and black powder substitute powders. These patches are convenient to use and make loading your muzzleloader easier. Jar of 100, 21/2" (works well with .45 & .50 Cal.). Notice for California consumers: WARNING: Cancer www.P65Warnings.ca.gov Technical Specifications T17 Products are specially formulated for use in cleaning away fouling from PyrodexÂ, Blackhorn 209 & Triple Seven Jar of 100, Diameter 21/2" works well with .45 & .50 Cal.