These are the famous PCB pagoda designed by Maarten Baert. Essentially they are a high performance omni CP VTX antenna. When they are made correctly, their performance is exceptional.

Specification:

Centre frequency 5.8 GHz
Frequency Range: 5550 6050 MHz
Gain: 1.1dB
Axial Ratio <1.3
Beam width: 360 degrees
RHCP
SMA Connector
Height: 90mm
Weight: 9grams