Technical Mechanical Group Engine Sequential Gearbox Speeds
MOC-79482 GTE Manual 8 Speed Gearbox | Letbricks
Amazon.com: LEGO Technic COMPLETE GEARBOX ASSEMBLY 2 x 4 x 3 1/3 Trans-Clear Wormbox gear motor REDUCER block Mindstorms robotics ev3 NXT transparent robot building power functions part 6588
DC Gearbox TT Motor to LEGO® compatible Cross Axle : ID 3810 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits