The Magnum Electric gooseneck jack Converter is an easy upgrade, designed to convert your SINGLE SPEED manual gooseneck trailer jack into a power jack capable of lifting up to 6,500 pounds of jack weight at 7 inches per minute. It comes standard with a manual crank backup shaft in case of battery failure. A 5/16" socket fits the backup shaft. This conversion will work with single or dual landing gear (one converter will raise single or dual jacks) and mounts on the right side of the jack leg. (At this writing, mounts are not available to mount on the left side of the jack) The Magnum Electric converter installs with basic hand tools. 2 year complete factory warranty. Made in the USA, Ellington, Missouri by Magnum Lift Systems. Electrify your manual trailer jack. From the square tube of the manual jack leg the electric lift extends to the right side (facing the front of the trailer/ tow vehicle drivers side) 12-3/4".