This manufacturer-approved and pinion gear (part number 41 C4220 a) is for the garage door opener. And sprocket gear 41 C4220 a to drive the chain, lifts and lowers the garage door. The assembly can also be used several parts; on your parts chart for a full list of matching parts. Pull the garage door drive before installing this replacement part. Follow the instructions in your operating instructions for the above and below limits you have installed this replacement part.