Description: This product is made of high quality and durable plastic. It can be installed in the outer wall or ceiling, prevent the pest into the room by net. And it is also a decoration of supply and exhaust vents of public, residential and industrial ventilation systems. You can keep indoor and outdoor air circulation through this ventilation grill. A good choice for your home, office or anywhere you want. Features: It can keep indoor and outdoor air circulation. Suitable for covering ceiling openings and ducting vents, practical and durable to use. Equipped with fly screen, it opens automatically when the wind blows. This material will not be corroded and very easily cleaned up. You can use it safely for a long time. It can be painted to match home's exterior as you want. Specification: Condition: 100% New Brand Material: Plastic Color: White Hole Inner Diameter: Approx. 5.14 mm Hole Outer Diameter: Approx. 9.44 mm Type(L x W): Approx. 15 x 15 cm / 5.91 x 5.91 inch 20 x 20 cm / 7.87 x 7.87 inch(Optional) Weight: Approx. 130g(15 x 15 cm) / 255g(20 x 20 cm) Package Included: 1 x Ventilation Grill Note: For different monitors, the color may vary slightly. Besides, please allow some errors of manual measurement, thank you for your understanding