i wanted to know before buying this item if it is compatible with the stick
Assuming the EX2 uses the same mounts as their other sticks:
A Hori EX 2 will take a Seimitsu stick, but you have to make sure you have the MS mount plate for this to work correctly.
The MS mount plate is the one that sort of resembles a JLF plate. The gate on the other hand does not matter what you use.