These Fan Replacement Kits are ideal for situations where you need to replace a worn out or defective fan. The 14-18" Kits include four #6 Stainless Steel Screws and four #6 Speed Nuts along with one Filter Screen and Fan of the appropriate voltage based on the unit you are repairing. & the 20" Kits include four #8 Stainless Steel Screws and four #8 Speed Nuts along with one Filter Screen and Fan of the appropriate voltage based on the unit you are repairing.