Abstract: A trailer jack comprising a vertically oriented vertically extendible jack and a mounting flange located on the jack. The mounting flange includes three bolt patterns. Each of the three bolt patterns includes a forward slot and two rear slots defined through the mounting flange. Each slot includes a longitudinal axis. The longitudinal axes of the slots of any single bolt pattern intersect at a bolt pattern axis that is closer to the forward slot than the rear slots. The longitudinal axes of the forward slots intersect at a central axis. The central axis is offset from each of the three bolt pattern axes. The rear slots of any of the bolt patterns are non-radial with regard to the central axis. The forward slot of any of the bolt patterns are radial with regard to the central axis.