See: Power HD Power HD have introduced the new HD WH-65KG waterproof servo for large scale cars. Featuring a fresh waterproof design, this high torque waterproof servo comes with durable stainless steel gears, and dual ball bearing. Measuring 65.8×30.0×55.6mm, the servo produces up to 65kg-cm of torque at a speed of down to 0.15s at 8.4V.