Genuine Bosch distributor cap to suit earlier style distributors with 'offset' clips (1963-1974). This cap has a small semi-circle cut out on the edge of the cap and a female cutout to accept a small male locating lug on the body of the distributor. If your distributor body has this small lug, you will need to fit this style cap regardless of the year of the car.
(Note 'offset' refers to the location of the clip relative to the plug lead outlet. Later style Bosch distributors have the clip equidistant between two of the lead outlets. The earlier ones have the clip locations close to the lead outlets. Please enquire if you need help!)