Aquasure AF-MEM100 Premier Series 3rd Stage 100 GPD High Performance Quick Twist Reverse Osmosis Water System Membrane NewThe Aquasure AF MEM100 is an incased high efficiency, high rejection reverse osmosis membrane that is built for our Premier Series under the sink Quick Twist Reverse Osmosis Drinking Water System. The high performance, high rejection 100 GPD RO membrane removes up to 99% of TDS (Total Dissolved Solids) in the water, providing the cleanest and healthiest water possible.