Constructed from three 1-1/2" Schedule 40 (48.3mm) black powder coated steel, this adapter is for 1-1/2" Schedule 40 (48.3mm) pipes and designed to support a Chair of Rickshaw Dolly. The central pipe holder which comes with an aluminum knob can be firmly tighten to support the chair is 90 degree crossover to other two parallel pipe holders. It allows you to connect two pipes with the M10 screws on the holders from the main structure of the Rickshaw dolly that offers a solid support for the Tee Pile Adapter.