Air CirculationThese circular air vents are designed to circulate air in your cabinets, shed, provide adequate ventilation, redirect air away from vent, maintain airflow to prevent moisture and mildew. Easy to AssembleThe side installation hole makes it easy to install and keep the grille in place. Diameter: A - 53mm, X - 64.5mm, these round air vents can be easily used to cover 52mm holes. Built to last Constructed of high quality stainless steel, the round air vents black have high corrosion resistance and high strength compared to standard grade vent covers which use thinner lower grade metal. Stylish smooth black finishModern black design of small round vents accentuates your decor and adds the finishing touch. The finish is smooth won"t hurt your fingers when installing. Multi-purposeThey are used for storage shed, suffice as soffit vent mesh, also can be used in covers of aquarium/solar generator/PC box/bedroom cupboards/cabin storage/kitchen cabinets for ventilation. Package includes 10-Pack of vent covers. About Shipping: All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and we'll make you feel satisfied.