Make sure this fitsby entering your model number. Motor Armature for Porter-Cable 7800 Drywall Sander – Fits PC 7800 Types 2, 3, 4, 5 and PC 7801 Type 1 Manufacturer Part Number #899519 Alternate Part Number #653108 Genuine PorterCable 7800 Drywall Sander Replacement Part Quality Motor Rebuild Parts