The key to disrupting the DNA of the bacteria is to ensure the water is exposed to the UV light for a long enough period of time. The SteriPen requires 48 seconds for 16 ounces of water, which is what makes it a viable option when traveling. It comes with an optional solar power charger as well so you're truly backcountry living.
Dimensions: L - 7.6" x W - 1.5" x H - 1.5"
Weight: 3.7 ounces without batteries, 8 ounces with batteries