UPRIGHT,LOWERSpecifications Item Description The Upright, Lower is a welded metal structural component measuring 50in L x 21in W x 16in H and weighing 338lb, serving as a critical load bearing element in the Tower Boom Assembly of the JLG 450AJ and 450A aerial work platforms. This part functions as the lower vertical support structure within the boom system, providing essential structural integrity for the platform's elevation and load capacity. One upright per