Plastic speedometer "20 tooth" gear drive, located in side rear of transmission housing. Fits "later" style Opel 4-speed manual transmissions (1971-1975) with 1.9L drivetrains. Also works with all automatic transmission Opel GT's 1968-1973. For use with 3.44:1 rear axle on some Kadett B and Manta/Ascona models.