Graupner, SPEED 400 m.Compact-dr. 4: 1,1719 This extremely light and compact geared drive is used in conjunction with the CAM GEAR PROP flip-up screw Part-no. 1324.28.20 or Order no. 1324.25.20 especially suitable for small, light sailing models up to approx. 1000 g weight. Only small NC cells from 0.5 - 0.8 Ah should be used. Retrofit ball bearing Part no. 221. Output Shaft dia 3.17 mm. Weight approx. 100 g