This is a A-NAA722C Seal, Retaining Collar PN: NAA722CMain Description As Following : A-NAA722C Seal, Retaining Collar P.N: NAA722C Dim A (1): REF. 4 Found in Section & Models : PTO Parts > PTO and Related Parts, Ford / New Holland TRACTOR: NAA (1953-54), Ford / New Holland TRACTOR: 900 SERIES Associated Items : New Also A-FO-O-NAA, A-FO-P-ACCESS, A-FO-P-SHERPS, A-FO-P-1400SHER, A-FO-S-NAA, A-FO-S-SHER-TRAN, A-SMFO19, A-FO-O-701-901, A-FO-O-701D901D, A-FO-P-ACCESS, A-FO-P-4CYLALL, A-FO-S-SELECTO, A-FRM-FOMM, A-SMFO20 And : Dim A (1): REF. 4 Inside Diameter: 1.1770" Length: 2.26" Outside Diameter: 1.6220"