W5SWL Brand Premium Series BNC Female to BNC Female Isolated Bulkhead RF Radio Connector - by W5SWL Brand BNC Female to Female Isolated Bulkhead Mount Connector Delrin Insulator, Gold Plated RF Pin, Nickle Plated Body Impedance: 50 Ohms Dave's Hobby Shop Premium Connector Series - by W5SWL by W5SWL Brand is Trademarked - Sold only by Dave's Hobby Shop and NO others. Premium Communications Connectors - not for Cable TV