A guard rail system fabricated from standard-sized components, preferably extruded, comprises balusters fastened to a lower rail and to an upper retainer at fixed intervals. The balusters are provided with central bores for receiving fasteners such as screws through predrilled holes in the upper retainer...http://www.google.es/patents/US6702259?utm_source=gb-gplus-sharePatente US6702259 - Guard rail system
