Injection-Molded Sprocket Set 8T Hex This four-pack of 8-tooth injection-molded sprockets comes with two idler sprockets (with 1/4" holes) and two sprockets with 3-mm hexagonal holes (for use with Tamiya Gearboxes that have 3-mm hex shafts).
Pololu 30T Track Set This track set includes a pair of 30-tooth silicone tracks, two drive sprockets measuring 1.38" (35 mm) in diameter, and two matching idler sprockets along with mounting hardware.
Tamiya 70142 Ladder-Chain & Sprocket Set The Tamiya 70142 Ladder-Chain & Sprocket Set includes 96 cm of chain and four sprocket wheels compatible with Tamiya gearboxes.
Mechanical accessories for robotics CBK6083
Tamiya 70100 Track and Wheel Set Track set for tank treads. Use these treads to create your own tank setup. These work superbly with the Tamiya dual gear box.