A CO2 inflator is a compact device used primarily for quickly inflating tires on bicycles. It works by releasing compressed carbon dioxide gas from a small cartridge into the tire, allowing for rapid inflation. This is especially useful for cyclists who experience flat tires during rides, as it saves time and effort compared to manual pumps. These inflators are lightweight and portable, making them easy to carry in a backpack or attached to a bike frame. Most CO2 inflators come with a nozzle that fits various valve types, ensuring compatibility with different tire systems.