The ARRMA HD Input Gear (13T) ​is a hybrid composite-and-metal replacement bevel gear designed for ARRMA 4X4 3S BLX, MEGA, and Boost platforms. 
It features a 13-tooth, 1.35-module composite gear molded onto a metal splined shaft to drive the main differential crown gear.
13-tooth bevel gear, 1.35 Module (1.35M)
Hybrid design with a composite gear molded onto a metal splined shaft.
Required Pairing: Must be used with a 37T 1.35M differential set (#ARA310872 or #ARA310956)