i have these Heavy Duty Bridging Ladders - 1220 x 310 x 50mm
i got mine direct from tracmat but just found them on ebay for
Heavy Duty 4 X 4 Bridging Ladders, Waffle Boards, on eBay (end time 19-Feb-10 22:16:28 GMT) on ebay
used them hard for 2 years and always did the trick, still not...