FOR 5 X 5 INCH DUCT OPENINGS – Surface-mount design fits HVAC ducts up to 4.88 x 4.88 inch OR SMALLER. Pre-drilled mounting holes spaced at 5.28 x 5.28 with screw hole diameter of 0.14 inches. Exterior (overall) size is 5.83 x 5.83 and grille thickness is 0.31 inches. Suitable for HVAC ducting ventilation, air intake or exhaust. EASY WALL OR CEILING MOUNTING – Pre-drilled screw holes allow quick and simple installation using just 4 screws (SCREWS NOT INCLUDED). Suitable as both - as a ceiling or wall vent cover, can be used as either air intake vent or air exhaust vent. DURABLE LIGHTWEIGHT MATERIAL – Constructed from impact-resistant, UV-stabilized plastic for reliable indoor or outdoor applications. Withstands temperatures from −4°F to 158°F. DUCTWORK PROTECTION – Plastic screen guard helps keep ventilation ducts clear of debris and unwanted objects. Perfect for heating, cooling or air conditioning - HVAC. Bathroom, kitchen and living room. VERSATILE USES – Works as a replacement for AC vent covers, return air vent covers, or intake vent covers in heating and cooling systems. Suitable for both residential and commercial HVAC applications. Our products are made out of quality plastic and coated steel. Each product is assured with long life and durability. Good compatibility with other ECOPRO VENT products.