Elastomeric expansion joint is specifically designed for plastic and FRP piping systems. Traditional spool-type or spherical-type expansion joints are too rigid and offer too much resistance to be used with FRP and other pipe. Style 261-R offers low spring rates and greater movements. Proco Products, Inc. 2431 N. Wigwam Dr. (95205), P.O. Box 590 Stockton, CA, 95201-0590