BetaFPV T Antenna 868MHz 80mm

The dipole T antenna is designed and manufactured by BETAFPV for a 2.4G/915MHz/868MHz receiver. This antenna is omnidirectional. RF balun circuit comes with this dipole antenna, just inside the injected rubber enclosure. Every piece of the antenna is tested with the frequency spectrograph to make sure it works in the correct status.

Which antenna should I choose?  Are these antennas compatible with other receivers like Frsky or TBS receivers?

First, it is compatible with any receiver with an IPEX MHF connector. Note that do NOT use the antenna with the wrong frequency. Even they look almost the same outside, but different balun circuit inside. It will have totally different performance in the wrong frequency point. Second, the shorter 915MHz/868MHz antenna is just made for small whoop drones. If you expect full-range performance, highly recommend the longer version.