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. Power HD 1812MG Servo SpecificationsTotal Height (A ) = 43.5mm. Body Width (B ) = 40.6mm. Below Mount (C ) = 26.5mm. Above Mount (D ) = 17mm. Total Length (E ) = 54.3mm. Total Width (F ) = 20mm. ? Learn how to install a steering servo correctly to increase steering performance, and avoid stripping your servo gears out.