The MAXPlanetary Base Kit is the entry point into using the MAXPlanetary System. This base kit includes a universal input stage, 1/2in hex socket output, hardware pack, 8mm keyed input coupler kit, and a 1/2in rounded hex shaft. Purchase a MAXPlanetary 3:1 Cartridge (REV-21-2101), MAXPlanetary 4:1 Cartridge (REV-21-2102), or MAXPlanetary 5:1 Cartridge (REV-21-2103) to complete your system. Add a NEO Brushless Motor (REV-21-1650) or an adapter kit if you want to use a different motor, like the new MAXPlanetary Falcon Spline Input Coupler (REV-21-2124) or MAXPlanetary Kraken X60 Compatible Input Coupler (REV-21-2138).