2pcs Rf Adapter Connector BNC Female to SMB Plug used in video signals BNC features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut SMB feature a snap-on coupling and are available in either 50  or 75  impedance. They offer excellent electrical performance from DC to 4 GHz. It has a frequency bandwidth, excellent performance, high reliability, long life characteristics application for Antennas, Wireless LAN Devices , Coaxial cable, Wi-Fi Radios External Antenna and so on