Riverdog, it is called a SideWinder. Almost any of the RV stores and towwable dealerships should have one that could be ordered at least. I recommend RV Upgrades to be my first choice; they are a major sponsor of this website and great people to do business with.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7