Yoder Smokers YS640 and YS640s Pellet Grill Cover New and improved for 2018, the Yoder Smokers YS640 and YS640s Pellet Grill Cover is custom designed to fit your smoker. This newly designed cover features a waterproof liner to stop water intrusion and is fitted with vents to mitigate condensation. This will keep your grills surface dry when not in use. Heavy-duty clips fasten the cover tightly over the shelves to keep out rain, wind, snow and other elements.