This is the 55Micro Waterproof Metal Gear Digital High Voltage Micro Servo. Designed specially to be a direct drop-in fit for the Traxxas TRX-4 with shifting servos and TRX-4M platforms, this small but mighty servo is high voltage capable with no need for BEC or to be bypassed! Additionally, the inclusion of the robust steel gears and the all CNC-machined aluminum case provide unparalleled durability and heat dissipation to ensure reliability under harsh conditions! NOTE: Not recommended for Heavy modified TRX-4M.Features: The ultimate upgrade for TRX-4 and TR-6 with shifting servos A great option for stock lightweight TRX-4M High voltage capable Waterproof design Durable all steel gears Fully Programmable with Reefs USB Link adaptor (SEHREEFS64 - Sold Separately) CNC-machined aluminum case Specifications: Speed: @6.0V: 0.11sec/60° @7.4V: 0.09sec/60° @8.4V: 0.08sec/60° Torque: @6.0V: 41oz-in (2.95kg-cm) @7.4V: 48oz-in (3.45kg-cm) @8.4V: 55oz-in (3.96kg-cm) Motor: Digital Coreless Operating Voltage: 4.8-8.4V Dimensions(LxWxH): 0.90x0.50x0.86in (22.9x12.8x22mm) Weight: 0.67oz (19g) Operating Spline: 25T Includes: (1) 55Micro Waterproof Metal Gear Digital Micro Servo Assorted Servo Horns and Mounting Hardware