This unique mobile base uses sliding side rails with pre-drilled holes and a spring-loaded pin. To adjust the size of the base simply pull the pin and slide the side rails to the desired position. Also available as an option is a set of four extra side rails that can be bolted to the existing side rails to extend their length. All four wheels can be independently locked. Two mobile base sizes are available: 457mm square to 711mm square with holding capacity of 275kg and 609mm square to 863mm square with holding capacity of 545kg.