DELTA 50-289 Mobile Machine Base for Unisaw with 52-Inch Unifence Heavy-gauge steel and features a foot-operated control lever that raises and lowers the base for easy movement and positioning For UNISAWS with 50-inch/52-inch Fences 20-5/8-inch by 20-5/8-inch Combines 50-273 and 50-284 Mobile base for Older Unisaws PRE-2009 with 52-Inch fence assembly, 1 crank handle mounted on front and other handle mounted on the side of the cabinet. Mobile machine base includes base, control lever, and adjustable foot pads