The O-Pen is the latest advancement in pocket water purifiers. It makes water safer by infusing it with a cloud of ozone gas. Used by water treatment plants and water bottlers worldwide, ozone is the strongest oxidizer available that can be safely used in water treatment.
Whether your adventures bring you to a quaint sidewalk restaurant in a foreign land, or you just want to drink from that cold mountain stream, you can rely on the Roving Blue O-Pen(R) to ensure that the water is safer to drink.
Partial List of Micro-organisms that Ozone Can Destroy:

Bacillus anthracis (Anthrax)

Cholera

Cryptosporidium

Giardia

Influenza

Poliovirus (Poliomyelitis)

Salmonella paratyphi (Enteric Fever)

Streptococcus faecalis

Bacteriophage (E. Coli)

Dysentery bacilli (Diarrhea)

Hepatitis

Legionella pneumophilia (Legionnaires' Disease)

Salmonella (food poisoning)

Salmonella typhosa (Typhoid Fever)

Tuberculosis

Additionally, there is no chance these organisms can develop a resistance to ozone. Best of all, when its job is done, ozone reverts to oxygen quickly, leaving no chemical residue, odors or tastes.
100% legal and permitted to bring on board all the airlines with you hand-carried, not checked luggage (due to the internal lithium battery), you can be sure that the tap water in your hotel room, cruise ship cabin, or nearby stream, is safe to drink, because with the O-Pen(R), the World is Your Water Bottle(TM)".
Advanced Technology
The O-Pen(R) is an advanced device housed in a black metal cartridge.
Fast-Acting
It will purify .5 L or 16 oz. of water in under one minute.
Ultra-Portable
The O-Pen(R) weighs only 1.2 oz. (30 g).
No Waste
Rechargeable battery w/ USB cable included. Purifies approximately 25+ liters per charge (about 50 uses).