【Widely Universal Fit】 Universal fit for 3/4" to 1-1/2" open-end drains. Seamlessly replaces old scuppers and fits most boat models, ideal for fishing, boating, and water sports. 【More Efficient Drainage】 High-capacity self-bailing design. The valve opens automatically under water pressure, providing 70% more drainage than traditional drains to keep your deck dry. 【Premium Durable Construction】Made of solid polyethylene ball, clear polycarbonate housing and PVC seal. Not easy to deform, with excellent sealing properties for long-lasting performance. 【Efficient Self-Draining】Utilizes neutral buoyancy for efficient drainage. The valve opens automatically under water pressure, keeping the deck dry and free from water accumulation.Mounted on the transom above the waterline. Seals automatically when waves hit or the boat rolls, preventing water and debris from entering the ship 【Quick Installation】Multiple mounting openings for easy installation/retrofitting. Comes with marine adhesive for sealing, no need to fill or re-drill holes.If you have any other questions, feel free to use the seller consultation service, and we will respond to you promptly