heavy duty ground protection boards 2×6 ft for architecture MasterSeal 975 Drain Board (DBS 6200) 4×50 ft. MasterSeal 975 Drain Board (formerly SonoHDPEeld DBS 6200). Polypropylene Drain Board System with Cut Protection Layer and fold out overlap flap. Flows 18 GPM/sqft veal rate. 4 Wide x 50 foot Roll (200 Sq. Ft.). Price/Roll.