Finally heavy-duty direct upgrade for plastic GWS 300/350 gearboxes. Features: - Aluminum body, dual ball bearing support for 10 x 10mm mounting stick - For any 20mm motor, 2.3mm shaft (Himaxx 2015 2025, Hacker B20) - Built-in cooling fins, no heat sink necessary - Comes with 3 ratios 6.6:1, 5.3:1, 4.4:1 - Aluminum adapter for 3mm shaft included - Use for any GWS planes as drop in replacement