FS-TFC 75 GPD Reverse Osmosis (RO) Membrane (removes fluoride) 75 gallon per day (GPD) water production can replace lesser 50, 36, or 24 GPD membranes Replaces membrane use in most name-brand systems and fits standard 2" diameter housings Produces water up to 97% pure and removes fluoride, iron, and heavy metals from your water Lasts 2-4 years with proper pre-treatment filters and timely replacement of these filters