Remove more than 99.9% of viruses, Bacteria, and protozoan cysts from water using only ultraviolet light with the Aqua UV water purifier from SteriPEN. Suitable for hikes, travel, or any situation when pure, drinkable water is not available, this water treatment device uses no chemicals. It wont change the taste or color of the water, or add an unpleasant smell. The unit runs on four AA batteries. A fresh set of disposable lithium batteries will power 150 one-liter treatments; rechargeable nimh batteries will provide 100 treatments, and alkaline batteries will yield 50 treatments. Simply press the on button, place the lamp in your water bottle and stir. In as little as 48 seconds, your water will be drinkable. The lamp automatically shuts off when the treatment is finished. The lamps lifespan is about 3, 000 treatments. The UV process alone does not Filter particulates, so filtering is recommended if solids are present in the water. The Aqua is compatible with the SteriPEN prefilter and SteriPEN fits all Filter, sold separately. Features: - eliminates over 99.9% of Bacteria, viruses, and protozoa - treats water in as little as 48 seconds - UV lamp provides up to 3, 000 liter water purification - powered by AA lithium disposable, rechargeable nimh or alkaline batteries - up to 150 one-liter treatments or 300 half-liter treatments with lithium batteries.