Triumph 712907 Spitfire Mk3 TR250 TR5 TR6 Choke Control Pictorial Black Knob
Note there fits on to the standard Lucas 1/4" hexagonal shaft with spring loaded retaining plunger. Knob head size 29.2mm x 29.2mm, Knob depth (27.3mm). As fitted to Triumph Spitfire Mk3 (US Models only from FDU31254), TR250, TR5, TR6 CR/CF.