I recently received a relatively new product the Sidewinder manufactured by SteriPEN. SteriPEN has been producing water purification devices using ultra violet light for some time. The difference between the Sidewinder and previous models is that it uses no batteries.
Ultra Violet light is a well proved method of water purification; it is used by many large municipal water districts. The Sidewinder destroys waterborne bacteria, protozoa such as giardia and cryptosporidium and viruses that could make you sick.
Ninety seconds cranking will purify one liter of water. It is simple to use, merely fill the one liter Tritan™ BPA-free water bottle with clear water, and screw it on to the Sidewinder. Then turn it upside down and crank for ninety seconds, when the green light comes on the water is pure. One of the down sides to using UV light is that the water needs to be clear and not cloudy. The Sidewinder is the first SteriPEN product to come with a pre-filter. You run the water through it as you fill the bottle.
The Sidewinder is larger and heavier than previous model of SteriPEN. It is 8.6 in. high, 5.5 in. wide and 3.8 in. in length. It weighs in at 16.6 oz empty. This makes it a little large and heavy for backpacking, but not impossible. Remember a one liter bottle is included. Because it will purify up to 8000 liters of water without changing the bulb it is very useful in emergency situations such as earthquakes or floods, camping, or anytime you are worried about your water purity.
I have played with the Sidewinder and found it easy to use. The only hard part is the cranking and an old man like me had no problem with it.
At a sales price of about $100.00 it is a great buy. I would recommend it