NetAlly's EXT-ANT-RPSMA external directional antenna, Reverse Polarity SMA connector for the NetAlly AirCheck G2 WLAN tester. The AirCheck G2 can use either the three internal antennas or this optional external antenna sold separately to locate APs and clients. In areas that have many rooms, such as in schools and hospitals, use the internal antennas to locate access points. In large, open areas, this optional external antenna can help you locate access points or clients more quickly.