This is a A-811-1018 Hexagon Slip Sleeve Yoke PN: 811-1018Main Description As Following : A-811-1018 Hexagon Slip Sleeve Yoke PN: 811-1018 Found in Section & Models : Driveline > Driveline Components, Neapco DOMESTIC: 1000 SERIES, Driveline > Yokes, Neapco DOMESTIC: 1000 SERIES Associated Items : New Also This is An Aftermarket Product And : Hexagon slip sleeve yoke. 1-1/8" bore with 5-1/2" centerline. Weasler alternative to original part. Bore: 1 1/8" Centerline: 5 1/2"