Pc-case 2pcs Electrical Wire Rf Adapter Connector RP-SMA Male to MCX Female used for mobile telephone antennas SMA is designed for use from DC to 18 GHz, but is most commonly used for hand-held radio and mobile telephone antennas, and more recently with WiFi antenna systems and USB software-defined radio dongles. It is also commonly used in radio astronomy, particularly at higher frequencies (5GHz+) MCX use a snap-on interface and usually have a 50  impedance (some are 75 ) . They offer broadband capability from DC to 6 GHz.[2] The contact surfaces are gold-plated. application for Antennas, Wireless LAN Devices , Coaxial cable, Wi-Fi Radios External Antenna and so on