FlexAirâ?¢ Magnum Fine Bubble Flexible Membrane Diffuser: Ideal for coarse bubble upgrades â?¢ Efficient geometry supports high-density installations of over 65% floor coverage â?¢ Non-buoyant design for reduced uplift and stress on mounting connection â?¢ Premium quality membranes available in EPDM, urethane, and Matrix Plusâ?¢ for reduced fouling and minimum maintenance â?¢ Non-metallic construction available for maximum chemical, temperature, and UV resistance. Triple-check valve design minimizes entry of liquid/solids into piping. Ideal for on/off applications