Porter Cable Replacement Lock Nut for 7800 Drywall Sander #877757 This part is compatible with models including; 7800,7800TY1,7801,7800TY2 Follow appropriate safety practices when installing nut 877757 Genuine Original Equipment Manufacturer (OEM) part. Compatible Brands: Porter Cable This manufacturer-approved nut (part number 877757) is a standard part that fits a variety of products