the cradles are 1" schedul 40 pvc. a "T" is cut and bolted with a couple bolts with locking nuts to the walker . shimmng a little to fit the walker helps. the actual cradles are not glued into the "T" fittings so they are interchangeable. customizing to fit your planes is easy. the guys at my flying field picked up on this idea and some handy modification such as hangers for transmitters and the like have shown up.