This is an optional Traxxas TRX-4M Complete Transmission & 87T Motor (Speed).
Transmission, complete (speed gearing) (9.7:1 reduction ratio) (includes Titan® 87T motor)
Boost the top end of your TRX-4M™ with this Speed transmission. The transmission features a high 9.7:1 reduction ratio for maximum speed. Traxxas Pro Built® transmissions come professionally assembled with a fresh new Titan® 180 87-turn motor. There’s no gear mesh to adjust or parts to align. The assembly bolts in as a complete unit for quick and easy installation.
