So I just wanted to pass on my experience with this topic. I bought a vivant gb2 glass break sensor to use with my 2gig gc3 panel. I was not able to make my 2gig “learn” the sensor. Not did tampering or pressing the test button trigger the sensor to the alarm. However testing the unit with simulated glass break did trigger the sensor and an alarm. So from what I can tell this sensor is indeed atleast somewhat compatible with the gc3 panel. I set it up as a “existing glass break sensor” and used the settings from a YouTube video to set it up. I had to manually enter the txid which was the last 7 digits. I hope this is of help to someone. Btw my glass break test was from a YouTube video of simulated glass breaking from a newer Samsung smart phone pressed up against the hearing sensor.