1、Excellent Material: Made of heavy duty plastic, wear resistant, durable and stable enough to withstand the harsh marine environment. 2、Function: The boat louver is designed to allow air to pass and keep unwanted elements out at the same time, is a great replacement for old vents on your boat. 3、Important Parameter: This vented version measures approximately 85 x 85mm, with approximate 70mm hole diameter, which is specially designed for straight through ventilation hose. 4、Universal Accessory: The heavy duty vent shutter is suitable for boats, caravan, RV with straight through venting hose, and the overall style is modern and stylish. 5、Easy to Install: High accuracy for fast and convenient installation in a short time and hardly require any mechanical expertise, and no modification, cutting or drilling required.