I have the same problem. I run my project on Unity 2019.4.2.f1, using SRanipal SDK 188.8.131.52. My desktop computer has a GPU GeForce 3080Ti which supports sampling rate of 240 fps. I followed the previously posted examples here to get the data using Callback function. To check the sampling rate, for each sample I also record the System time in ms. Genrerally, I get data at a sampling rate of 240 Hz (stable ~ 5ms between consecutive samples according to the System timestamps). I expected to consistently have eye data repeating twice since the sampling rate of the eye tracker is 120 Hz. However, when looking at the frame_sequence, sadly the recording of the eye data is not consistent at all: sometimes the frame count jumps 3 frames, sometimes 2, sometimes more or less. So, I end up with a bunch of identical lines of eye data and at the same times loos a lot of frames in between. Any suggestion how to get stably sampled eye data? Highly appreciate it!