Check the listing for details. GC Electronics TV Interference Filter 18-520. NOS. Condition: New. Listed at 5.99 USD. This GC Electronics TV Interference Filter 18-520 is a great addition to any radio communication setup. It is designed to filter out any interference that may affect your reception, ensuring that you get the best possible signal quality. The filter is universal and compatible with many different brands, making it a versatile choice for any user. The item is brand new and has never been used before. It is a NOS (New Old Stock) item, which means that it is a vintage product that has never been sold or used before. Despite its age, the item is in perfect working condition and is sure to provide you with the reliable performance you need. Whether you're a professional radio operator or just a hobbyist, this interference filter is sure to meet your needs. Item is brand new old stock in very good condition. Thank you.