The Jefa linear drive is a strong and compact autopilot drive and much more efficient than existing hydraulic and electro-mechanical linear autopilot drive units.With a thrust of 400 Kgs on 250 mm centers it's much stronger than a human being (the max. output torque of 100 KgM is equivalent to 100 Kg force on the end of a 1 meter steering tiller) and is build for 24 hours per day continuous operation with a total weight of only 6,6 Kgs. The combination of the flat wound (pancake) electric motor with the ultra efficient planetary gearbox results in an extremely efficient drive unit to keep the battery charging time to the minimum. The drive can be used on boats from 20 to 45 foot l.o.a. (or up to 100 Kgm rudder torque) equipped with a mechanical steering system that can be back driven. The linear drive drives the rudder via the existing tiller arm or quadrant or via an independent tiller arm.