A nut driver for driving nuts of various sizes includes an elongated housing with opposing driver and handle ends. The driver end is open and assumes a largest size. A rigid collar and plunger are fixed about the housing and positioned at any of a number of selectable radial positions, each of which is associated with a different nut size. A plurality of nested sockets are each slidably movable by the plunger between forward and rearward positions. Each socket has a foot adapted for contacting the plunger at one of the selectable radial positions. The elongated housing is preferably separated into two sections, including a handle and a two-sided socket mechanism that includes two opposing driver ends each having sockets of different sizes.