Description Over-running Coupler for Tractor up to 75 PTO H.P. - Steel welded housing, heat-treated alloy steel inner sleeve, gun lubrication, can operate at 1000 RPM - Extends PTO 4 7/16" - 1 1/8", 6 spline female x 1 1/8", 6 spline male. This item is a suitable alternative for the following: 442-3100690, 033100690, 442-033100690, 48A29, C690F