the channel members 60 of both workpiece holders 100 and 100 39 respectively to the final height with the base of the leg members 10 angled out slightly from the vertical axis to the wall that the workpiece is being fastened to the operator then locks the clamping means 70 on both workpiece holders 100 and 100 39 and secures the pair of channels 60 to each of the center beam 30 the cabinet is then placed onto the installation plates 150 and 150 39 on top plates 95 95 39 respectively of the workpiece holders 100 100 39 and the final adjustment to the desired height is accomplished after 158 and 158 39 are placed against the wall and then by kicking the foot member 10 and 10 39 of each workpiece holder toward the wall until the workpiece is positioned at the desired height to verify the level of the workpiece the liquid bubble level devices 115 129 139 respectively are checked and appropriate adjustments of the workpiece holder 100 100 39 are made after the workpiece is moved against the wall framework and elevated upwardly to the appropriate position the workpiece is screwed or otherwise affixed permanently in place once the cabinet c or other similar object is secured to the wall the operator releases the workpiece holders 100 100 39 by placing his foot on the handle 29 so as to raise the spring biased collared fastener 40 toward the top member 95 and thus disengage the fastener 40 from the partial hole 6 in the strut member 20 this causes the channel member to pivot and disengage from the workpiece to install one cabinet c next to another cabinet c 39 the operator places the top plate member 95 of the workpiece holder.