You need the Replacement Dome for Fan-Tastic Vent RV Roof Vents, # FVK1020-19, it fits models FV801200, FV801208, FV801250, FV807350, FV802250, FV803350, and FV800900.
I suggest you also consider one the Ultra Breeze vent covers, # FVU1500WH, or # DMC38FR to give you the ability to utilize your fan and vent in all weather conditions and even when towing. It will also protect that Lid from damage. view full answer...