Valve guide, exhaust, suit Norton twins and early Commando 750 (1949- 1972), each. Also inlet guide for motors pre 1963. OD 0.0501 inch 2 required per motor, cast iron, see 062725 for inlet guideOriginal part numbers:D12/140; K12/140; T2011; 062725 - valve guide (inlet or exhaust)063527 -