This is a New IPTO  Drive Gear / Shaft for IH Farmall tractors 1566 and 1568. This gear has 1 7/8"  18 spline  and 26 gear teeth 25 degree.   You must specify your tractor model and serial number. send email to schmittfarmserv@wwt.net  This is a  NEW gear  not a used gear with new splines welded on. I also have  carriers and gears available for other applications  along with release bearings and other clutch and PTO components  Check out my store for other IH  parts.   I have over 25 yrs. experience of rebuilding IH tractor and motors and have many parts available . Email your questions and I can probably help you.