Camco Flying Insect Screen -Protects RV Furnaces From Insects and Prevents RV Vent Damage - (2 Pack) (42141) Screen measures 2-7/8" diameter x 1-5/16" tall Fits most Duo-therm and Suburban furnace vents Protects the furnace from flying insect nests Easy to install, includes tool Heavy-duty stainless steel mesh cover