The KONTRONIK Spur Gear (KSG) In combination with the PYRO 850-50L or PYRO 1000-48L the KONTRONIK spur gear (KSG) is a real innovation especially for airplanes. It fits perfectly for towplanes and 100 / 120 scale models. The KSG can be used, where gas engines are forbidden: silent, clean, odorless. The KSG offers multiple possibilities of mounting. Depending on the version, it can be mounted on the front, on the back or the sides. Despite its power, it has a very compact construction (BHT 132 x 108,3 x 135,5 mm when mounted on the back) and light weight (ca. 1.300 resp. 1.500 g motor included). Further features are a combination of gear wheels materials that are more resistant to wear and special ball bearings. The gear ratio is 4:1. The KSG is designed to operate with the PYRO 850-50L or PYRO 1000-48L.Customers who already own a PYRO 850-50L or PYRO 1000-48L, can send the motor to us and we mount it free of charge. However the KSG is not sold individually, because the installation is complicated and the KSG is approved for the above-mentioned motors only.