Fogger Replacement Disc 6-pack This is a High Quality 20mm disc replacement for most fogger mister units. It includes 6 discs and key. The Key is used to remove the small ring around the inserted disc, That holds the disc in place, in your fogger unit. Each disc is coated to extend the life. These discs will come with a black rubber protector ring. Remove it before installing into you mister. We also offer a 16mm smaller size. Not as popular.