Regular: for municipal water, designed as a bottled water replacement. Filters chlorine, chemicals (VOCs), heavy metals, radon 222, and fluoride.
Standard: for any in- or outdoor use (non-turbid, non-stagnant water). Filters aesthetics (such as chlorine, sediment, dirt), biologicals (such as giardia, cryptosporidium, e-coli bacteria), chemicals (VOCs such as DDT, MTBE, benzene, chloroforms/THMs), dissolved solids (heavy metals such as arsenic, lead, mercury, copper, zinc, aluminum, chromium 6), and fluoride.
Advanced: same media as standard filter, plus iodinated resin. Filters as standard filter, plus bacteria and virus.
Radiological: same media as standard filter (?), plus filters radiological contaminants (such as gross beta, radon 222, alpha radium 226, plutonium, uranium, cesium 137 and radioactive iodine 131.
More information at www.seychelle.com/technology_about.php.