This assembly is designed to be used with the Humminbird MEGA 360, thus the shaft is not included. ?The ALCS, Aluminum Cross Shaft and base that mounts to either a 7/8 or 1 inch rail.??The 360 shaft slides into the knuckle, which can be tightened. It comes with a depth collar so you can always set the transducer to the desired depth. When traveling you can rotate the assembly 90 degrees so the transducer is out of the water and secure.