This hand control is used with a Von Weise low volt motor system.  The connector on the end of the hand control cord has a small square four prong plug.

NOTE: the control you will receive will look a little different than the one pictured, but will work the same, except that the replacement control will not be lighted.  The original control pictured is not available any longer; neither is any other component of the low volt Von Weise electronics set, but we found a company that could manufacture this replacement hand control.