The coupling Pins available in:
9" Pin W/1"Collar(Outside Diameters in: 1.25", 1.375", 1.44")
9" Pin W/1/2" Collar ( Outside Diameter in: 1.375")
9" Pin W/ 1/8" Collar( Outside Diameters in: 1.25"&1.375")
7" Pin W/out Collar (Outside Diameter in: 1.44")