Furnace And Battery Vent; Mud Dauber Screen; Square; For Use With Atwood Models 2540/ 8516/ 8520/ 8525/ 8531/ 8535 And 8940; 4-1/2 Inch Length x 4-1/2 Inch Width x 1-5/16 Inch Height; Stainless Steel Mesh Cover; Single; With 2 Spring Fasteners And 1 Installation Tool