Durable Material: Air Vent Grille Made of 316 stainless steel material, polished surface, corrosion resistance, sturdy and durable to use. Size: The Round Air Vent measures 125mm(5inch) in diameter, 4 drill holes(3.5mm), easy to install; and the air volume is adjustable to meet your need. Adjustable Ventilation: Our Incoming Air can be used for indoor exhaust. suitable for heating or ventilation of a boat, mobile home or caravan, adjustable ventilation, change of fresh air according to your needs. Designed For: Our round ventilation grille is professional designed for Yacht, boat, Camper, roller shutter, ventilation panel, ideal for lifting and improving air circulation. Wide Application: The round ventilation grille can be used indoors as well as outdoors for anyone who needs adjustable ventilation. Heat can be generated according to the grilled food. Even garages can be optimally ventilated with these ventilation rosettes. Note: The data are all measured manually, please allow an error of 1-3 cm due to differences in light and display, there may be color differences, please refer to the actual item received. 2Pcs Round Air Vent Grille, 125 mm Round Stainless Steel Ventilation Grille Air Vent Duct Mosquito Net Exhaust Grille Incoming Air Exhaust Ventilation Adjustable Shutters