The Power Products Standard Desiccant Air Dryer Cartridge is designed to fit AD-9 air dryer applications and helps to prevent equipment damage and minimize downtime. It works by removing moisture from the air, which helps to protect the brake system from corrosion and rust. This desiccant air dryer cartridge is easy to install and is a great way to keep your vehicle or equipment running smoothly. FleetPride is your First Click in Heavy Duty®.