NF2999SM Synthetic Media Blank Coolant Filter is a high quality, long-life coolant filter has been specially designed for use with liquid cooling treatment. It will last as long as 150,000 miles or 15 months. The NF2999SM features an inner shell with a tough epoxy coating to guard against rust caused by low corrosion inhibitor protection. The outer shell is coated with baked enamel to prevent intrusive rust from causing leaks. Penray synthetic media filters contain three distinct layers; 1. heavy-duty wire mesh, 2. polyester fiber binder and 3. fiberglass mat for ultimate filtration.