Water purifier manufacturer SteriPEN has updated its lineup of portable products, with a UV-based unit called the SteriPEN Freedom. Billed as the smallest, lightest and first rechargeable UV water purifier on the market, it disinfects up to 16 oz (0.5 L) of water in 48 seconds.

We've previously covered numerous water purification solutions for the developing world, with LifeStraw, Moringa tree seeds, or even banana peels being notable examples. The new SteriPEN device, however, is defined as hiking and camping equipment by its manufacturer, rather than as a life-saving tool.

The Freedom features a germicidal UV light which destroys 99.9 percent of bacteria, viruses and protozoa. Forty-eight seconds is enough for the Freedom to deal with half a liter of water, while a liter simply requires repeating this operation. A green light gauge indicates when it's safe to drink the water.

Recharged via a micro USB B port from a computer, AC outlet or a compatible solar charger, the Freedom offers up to 40 treatments on a single charge. The overall battery and UV lamp life is estimated to last for 8,000 treatments of 16 oz (0.5 L). The device also serves as a flashlight.

Equipped with a removable lamp cover, the new purifier weighs in at 2.6 oz (74 g) and measures 13 x 3.5 x 2.2 cm (5.1 x 1.4 x 0.8 in). Sold with a USB cable, AC adapter and neoprene case, the SteriPEN Freedom will be available starting this fall (northern hemisphere), priced at US$119.95.