The versatile standard prop is available in four sizes which provide a range of propping heights from 1.676m to 4.876m. Props are multi-functional and can be used to back- prop both beams and slabs until the concrete has cured. They are also widely used to support box floor centres on which decking plates are placed to form light slabs suitable for low cost housing developments. The box floor centres are adjustable to cater for different widths between walls. The three sizes of box floor centres allow for a minimum span of 1.219m up to a maximum of 4.724m.