1-3/8" To 1-3/8" Ford Ag Tractor Pto Shaft Over Running Coupler Coupling C660F Coupler is rated at 75 hp. max. Female end is 1.375" 6 Spline, male end is 1.375 6 spline. Overrunning clutch-pin style. Replaces Part Number: 03-31-00010, 03-31-00660, 48A26A, C660F, B500216 48A26, 16063000, SPC16630, ORC660F, C950, 103168