Purchased for $99 from Amazon here on April 12, 2022
This antenna was given a full 3D spherical swept gain test program with gain measured in over 400 physical directions and at 200 frequencies. This kind of testing helps you visualize the full radiation sphere. With normal intended installation the antenna would be pointed in the Z axis in these diagrams with intended gain towards the horizon.
Marketed as a 12 dBi circularly polarized antenna, actual measured gain was as follows: 902 MHz +8.6 dBi; 915 MHz +8.5 dBi; 928 MHz 8.3 dBi.
As often is the case when marketed to consumers, this antenna falls short of the expected gain by 3.5 dB.
The antenna is indeed circularly polarized with RCHP gain being +8.0 dBic and LHCP of -1.5 dBic at 915 MHz. The axial ratio is poor, only 6.1 dB at 915 MHz broadside (Z Axis), degrading to 7.9 dB at 902 MHz. An axial ratio of 8 dB means the antenna would have an 8 dB change is response to slanted linear fields, where a good axial ratio would be close to 0 dB (truly circular and rotation independent). The images below are all click-to-enlarge.