Ray Allen Servos were designed specifically to control trim surfaced in homebuilt aircraft. They can also be used to operate other mechanisms within your aircraft, thus eliminating the need for bulky cables and pulleys. Ray Allen servos operate on 12-14 volts DC. When activated they push or pull with tremendous force. Since this thrust is generated by means of a jackshaft (T2 series) or jackscrew (T3 series), the output shaft will lock in any position when the electrical power is off. They will automatically stop when their travel limit is reached. No electronics are used to control Ray Allen servos and they will not travel unless power is switched on by the pilot. Ray Allen has three different T2 and T3 servos available: The T2-7A servo has .7 inch travel. The T2-10A servo has 1.0 inch travel. The T3-12A servo has 1.2 inch travel. Check the specifications for a servo output travel that best suits your application. A Ray Allen servo is included in a Ray Allen Trim System, (along with indicator, rocker switch and clevis/pushrod kit), or can be purchased individually.