SSM 2
That's a TRS gimbal. It has 1/2" studs to mount the outdrve and the small propshaft. Plus the small trim rams.
They're rare, and valuable. But if you break one you'll learn why they're rare and valuable. Power handling was less than the TRS. All of them I ever saw were set so low in X that it wasn't funny. They were a few inches longer than a TRS.