Ultra-Drain Seals® Mats, Square, 24" L x 24" WStops spills from going down the drain Reinforced mesh is "sandwiched" between layers of polyurethane which increases durability and resistance to tearing Unique, urethane construction allows the pad to deform and seal off most drains and temporarily "seals" to any smooth surface A valuable addition to any emergency response plan, spill kit or stormwater management program Both sides will quickly seal drains (there is no specific top or bottom)