The Konstruk-Tubes tubular building set was created in 2006 by of Bradenton, Florida. Keith Lock, a paramedic, invented the toy after seeing his children play with some PVC pipe and fittings. Larger Image The basis of the set is simple, Polypropylene tubes and connectors. Lock added some unique designs to his connectors however. Basic shapes such as 90 degree elbows and Tee connectors are used, but more complex and specialized connectors are implemented as well, enabling a more diverse set of constructions than with just the simple shapes.