This is the later style engine block knock sensor for the ignition and or turbo APC system computer from a 1991 Saab 900 2.0L 16V turbo engine. The application is also used on the 1991 - 1994 2.1L 16V Non-Turbo and the earlier 2.0L non-turbo engines starting in 1986. The later Classic Saab 900 uses this Saab  part # 75 68 801 with a differnt bolt. This is Bosch part # 0 261 231 006. This later style part can be fitted to the earlier Classic Saab 900 cars as well. I believe it uses a different bolt and those early knock sensors were shaped slightly differently, but the electrical connector is the same.