NSF Certified; 1/2 micron filtration; lead removal; limescale control. The H-54 reduces lead, off-tastes, odors, chlorine, dirt, rust, parasitic protozoan cysts such as cryptosporidium & giardia, asbestos fibers, & all particles ½ micron & larger in size. It also inhibits scale build-up on water-dispensing appliances. Contains a lime-scale inhibitor feature to extend appliance life.