This travel-sized water purifier is equipped with a new optical water sensor that activates the lamp only when it's immersed. When the lamp is immersed shortwave ultraviolet light disrupts the DNA of bacteria, viruses, and protozoa, rendering them harmless.

The device is intended for treating clear water. It has also been shown to reduce microbial contamination in mildly turbid water, but you should consider an alternate purification system. If you do use it in turbid water, follow the package instructions carefully.

Ideal for use in cups, mugs, water bottles, and canteens.
The optical water sensor detects whether or not the device is in water and only allows the UV lamp to activate when the SteriPEN is immersed.
No pumping, chemicals, test strips, extended time-keeping, or filters required.
Purifies 470ml of water (cold or warm) in less than one minute, or 950ml in a minute and a half.
Lamp life is approximately 8000 treatments.
Includes two non-rechargeable lithium CR123 batteries.
Manufacturer's tests indicate that disposable CR123 batteries will treat approximately 50L of water, while rechargeables will treat approximately 25L of water.
Note: Colder temperatures will reduce the number of doses per battery charge. In cold conditions, warm it to above 0°C before using, and store the batteries in your pocket or other warm location