TFL Integrated Drive System . Suitable for 36 mm Diameter Brushless Motor Motor Direct Mount to it with Shortest Flex shaft given out Maximum Power and efficiency. 4.73mm Shaft Shaft and Adjustable Prop Out angle. Fully made in Al Alloy Length 19cm (12cm OutBoard) x Width 3.8cm x Height 4cm Outboard Opening Hole W 35mm x H 40mm Weight 99g