The 24" x 48" x 2" bench backer boards create a perfect waterproof seating solution (both shower benches and shower seats) for your shower, and are designed to integrate with the Everbilt shower system. These lightweight, stable, and load bearing backer boards are waterproof and vapor-resistant, consisting of an extruded polystyrene rigid foam core that is reinforced with glass fiber mesh with alkali-resistant finish on both sides and coated with a polymer-modified cement. These shower benches and seats install much quicker and easier than metal tray or concrete seats, and are ready to tile. Plus, these bench backer boards bond well to modified thin-set mortar. Pairs well with Everbilt screws and washers. This package includes three waterproof backer board pieces to build your optimal shower bench or seat.