This remains one of our favorite antennas because of the solid construction and now and even lower price! Antennas are right handed circular polarized antenna (RHCP). Comes as a Tx / Rx set or two Tx antennas.
For Fatshark / Immersion choose SMA. For Boscam and other equipment, choose RP-SMA. The SMA connector on the antenna has the needle and the RP-SMA has the hole.
We recommend popping the cap off the antenna before you fly and applying some GOOP or other adhesive to reinforce it.