Clean Air Nano Tech ERV, HRV core The world best membranes for ERV and HRV.- DUO-CLEANTM generates the best performance for your ERV and HRV.- Great durability and stability.- Flammability qualified with UL 94.- Using eco-friendly materials.Specialized fine cutting process.- Low pressure drop with enhanced performance.- Great fitting with special aluminum frames.- Easy installations with precise dimension.Technical advantages.- Performance forecasting software.- Accumulated test data and pre-certification test.- Optimized size and air-flow analysis propose.