TRX3998 Two speed Conversion kit E-Max !

TRX4400 TRX Pro.15 to TRX 2.5/2.5R upgrade kit for Nitro Rustler, Nitro Sport (incl. SE), and Nitro Stampede !

TRX4800 Pro.15 to TRX 2.5/2.5R upgrade kit for Nitro 4-Tec, Nitro 4-Tec Pro !

TRX4900 Pro.15 to TRX 2.5/2.5R upgrade kit for T-Maxx !

TRX4981X Diff. spool !

TRX5191X 4-Wheel Drive upgrade kit (includes all parts to add 4WD to SportMaxx) !

TRX5192X Two-speed upgrade package (all parts to install a two-speed in a SportMaxx) !

TRX5193X Single-speed conversion kit (Eliminates two-speed mechanism for reduced weight, less rotational mass) !

TRX5194X Reverse upgrade kit (includes all parts to add reverse to SportMaxx)(includes 2018 servo) !

TRX5270R EZ-Start 2, complete system with controller, drive unit, wiring harness !