PRO-PLUS® Trench Drains Josam revolutionized the drainage industry with the PRO-PLUS® Trench Drain System. It's manufactured using glass-fiber reinforced polyester (GRP) pressed from sheet molding compound (SMC), which is a composite of polyester resin, mineral fillers, and glass -fiber mats. SMC is a tried and tested GRP material with extremely high strength and dimensional stability. Learn more here Filter by 200 PRO-SNAP® Grates Load Class C Load Class E Load Class F 200 Locking Bar/Bolt Down Grates Load Class A Load Class C Load Class E Load Class F 200-DIS-F-PS – DI Slotted Pro-Snap Grate, 1/2 Meter, Load Class "F", 8" Width