Countertop Water Filter Purifier Unit KDF GAC - Great for apartments, dorms, RV's or travel. Removes Chlorine, Lead, Chemicals, Heavy Metals. Leaves beneficial minerals, such as calcium and magnesium, intact. Tested to industry standard NSF-53 protocol by independent laboratory. Convenient - quality water right at your tap. Economical - costs about a penny per gallon for "better than bottled" quality.