Exen’s FRP (Fiberglass Reinforced Plastic) odor-control cover system is used in distribution boxes, sedimentation tanks, reaction tanks, digestion tanks, and thickeners of sewage and wastewater treatment plants for the prevention of malodor diffusion. It comes in different shapes: dome, round, flat, and the like. Compared with other odor-control cover systems, the FRP odor-control cover system is very economical, which can be used in diverse settings.