the easiest way for a novice is to take your serial number to your dealer, and he can print off a build sheet for your tractor.

of course if your not the original owner somebody else could have added it down the road.    to verify yourself lift the engine hood up and in the space between the engine and cab firewall, you will see a hydraulic valve, with electrical solenoids on it, that'd be a "factory" one.

otherwise a after market valve would be mounted to the side of the tractor frame right in front of the cab, or mounted on the rear, right above the hydraulic remote ports.