Servos are powered by the ESC's output to the receiver. If you're using a higher-strength servo than the ESC can support (usually greater than 20kg), you may experience 'brown-outs' where the radio signal can be interrupted and cause erratic driving. This can be helped by plugging a Glitch Buster into the receiver smoothing the current delivery. However, in some cases, you may need to install an external BEC. FitmentIf fitted to a Traxxas TRX-4/6, it is unlikely the stock electronics will be able to support the increased power demands of this servo. It is strongly recommended to use an external BEC . Power HD LW-25MG Servo Specifications. Total Height (A ) = 44mm. Body Width (B ) = 41mm. Below Mount (C ) = 28mm. Above Mount (D ) = 16mm. Total Length (E ) = 54mm. Total Width (F ) = 20.5mm. ? Learn how to install a steering servo correctly to increase steering performance, and avoid stripping your servo gears out.