The Garmin GNX 21 is a high-quality marine instrument display that provides sailors with essential information about their vessel's performance and surroundings. With a 4-inch LCD screen, the GNX 21 displays data such as speed, depth, wind direction, and more, making it an essential tool for any sailor. The device is designed to be durable and waterproof, making it suitable for use in harsh marine environments. To protect the GNX 21's screen from scratches and damage, our website offers a range of screen protectors that are easy to install and provide long-lasting protection.