Experience cleaner air with the Guardian Lb4000 B Filter, a high-quality cartridge designed to enhance your HVAC system's performance. Compatible with a wide range of Guardian models, this filter is engineered to capture particles and allergens, ensuring a healthier indoor environment. The lb unit type specification denotes the filter's efficiency in removing airborne particles, making it an ideal choice for households and offices looking to improve their air quality. Trust in the Guardian brand to provide a reliable and durable filtration solution that fits seamlessly into your existing setup.