Shop Fox Adjustable Mobile Base Extra Heavy-Duty. The heavy-duty casters are arranged on outriggers allowing the machine to sit as low as possible and yet be extremely stable. Swivel casters on two corners provide excellent maneuverability. The bolt pattern on the fixed caster side allows orientation of the wheels in either of two directions. The base can be assembled in any of eight configurations providing maximum flexibility of use. The unique two piece retractable feet use rare earth magnets to allow the knob to turn while the foot pad is tight to the floor. You will find these mobile bases to be far superior to any mobile base on the market in strength adjustability and movability. This patented mobile base is the most stable on the market with outrigger type supports. D2058A adjusts from 18-1/2" x 24-1/2" to 28-1/2" x 33-1/2" and weighs 34.6 lbs D2057A adjusts from 19" x 20-1/2" to 29-1/2" by 29-1/2" and weighs 30.9 lbs. Specifications for Shop Fox Adjustable Mobile Base: Manufacturer: Shop Fox Condition: New Package Contents: Shop Fox Adjustable Mobile Base Shop Fox D2058A Adjustable Mobile Base Extra Heavy-Duty