The best thing to do is put the radio in to test mode and read the controller board version. To put a STX in to test mode, do the following:
1. With the antenna up, the accessory connector facing towards you, and the front of the radio facing to your right, find the second and fourth pins down on the right side of the connector.
2. Turn on the radio while shorting out these pins. It will beep, and you will be in test mode.
2. The controller board version will flash on the screen. VER controllers will only do type I systems. You want a REL (STX 821), GPS, or GPL controller. They do type II.
Let me know if you have any questions.
Jeff