Gearbox inner rubber gaiter. Fits over the rear 'tower' of the gearbox where the gear lever attaches to the gearbox on 101 and 105 Series 5 speed gearboxes. Fitted to all mechanical clutch cars and hydraulic clutch up until the early 1970s (and occasionally even on later cars) that do not have the 'combined' gaiter (available under GB022) fitted.