CURT Xtra Duty Class 5 Trailer Hitch, 2-In Receiver, Compatible with Select Chevrolet, GMC C-Series, K-Series Model 15317CURT Xtra Duty Class 5 Trailer Hitch, 2 In Receiver, Compatible with Select Chevrolet, GMC C Series, K Series Model 15317 When we came to the limits of towing capacity, we wanted to know what else was out there. What could we discover off the beaten path? So, we kept going. CURT class 5 Xtra Duty hitches begin a class of their own, beyond class 4 and beyond anything the standards dictate. They are designed for the hard road where only full size pickup