Art Mould manufactures a complete line of Beam Bolsters and Slab Bolsters.  Our Heavy Duty Beam Bolsters are reinforced with plastic coated steel and our all plastic Slab Bolsters can be clipped together to create any length.  Manufactured in various heights with corrugations spaced 1" on centre to serve as guides for bar spacing with an arch design to maximize strength between legs.  Packaged in boxes or pre-snapped together and strapped.