X base and upright are made of rectangular tubing. Arms are independently adjustable every 3" from 48" to 72". Inner arm uprights are made of 0.83" square tubing with blade rectangular arms measuring 1/2"X1-1/2". Heavy-duty "X" style base comes with casters included. Additional Details ------------------------------ Product description: X base and upright are made of rectangular tubing. Arms are independently adjustable every 3" from 48" to 72". Inner arm uprights are made of 0.83" square tubing with blade rectangular arms measuring 1/2"X1-1/2". Heavy-duty "X" style base comes with casters included.