ITEM NAME:4x 316 Stainless Steel Round Marine Louver Air Vent Ventilation Gille Cover Description: 100% Brand new and high quality. Marine Grade stainless steel 316, durable construction. Mirror finish, corrosion resistance and durable. Side Knob Opening Mechanism Easy to stall,convenience to use. Suitable for related vents in boats, marine, yacht, caravan, home Specification: Material:316 stainless steel Size Chart: Diameter:Approx. 128mm/5.0inch Package Includes: 4 Pieces Louvre Air Vent SKU: DMO0019366619525786.4 Pieces Louvre Air Vent. Marine Grade stainless steel 316, durable construction. Material:316 stainless steel. Easy to stall,convenience to use.