These 100% cotton patches are pre-lubricated for easier loading and easier cleanup. Thickness varies from 0.005" to 0.020" and are dsigned for use with a round ball of approximately .010" less than caliber, example would be a 50 caliber rifle uses one of these patches with a .490" diameter lead ball. Patches are tightly woven cotton and are resistant to burning. Please check with your firearm's manufacturer for recommended lead ball and patch sizes. Patches are packaged per 100.