Brio wooden train bridge supports that uses Duplo lego as pillars. With this collection you should be able to build as complex bridges as you like. 2013-08-18 Update Increased the size of the female part with 0,5 mm because it was a little tight.This thing is made to work with the standard 215 mm straight. For the first level columns use three Duplo blocks and seven blocks for the second level columns.