This Thetford 94219
Black City Water Dish With Brass Check Valve is an original
manufacturers replacement dish type water fill with a 3-1/2 inch
opening. The brass check valve has a 1/2 inch M.P.T. fitting. The dish
is constructed of durable plastic for a long life. It will not discolor
or fade and is impact resistant. It also comes with a replacement rubber
dust cover to keep dirt and debris from your fresh water supply. The
Cut Out Dimension is 3-1/2 inches and the Outside Dimension is 4-1/2
inches.