Ultra Compact 8+N+R Sequential Gearbox - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
Technical Mechanical Group Engine Sequential Gearbox Speeds
Leic Power Functions Motor Set 113Pcs MOC Electric 6-Speed Synchronous Gearbox Assembly Kit with M Motor Compatible with Lego Technic : Amazon.co.uk: Toys & Games
Compact symmetrical 4 speed AWD gearbox with differential lock from BrickLink Studio
Ultra Compact 8 Speed Sequential Gearbox - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums