Steripen Pre-Filter
When clear water is not available, the Pre-Filter filters out particulates and debris with its 40 micron filtration screen, so that UV light can then be used to effectively destroy the microorganisms in it.
It forms a watertight seal with Steripen® Classic 3 and Steripen® Ultra,™ and fits most wide-mouth water bottles.
To use, simply pour water through the durable 40x40 micron screen filter cartridge to fill the bottle. Then you’re ready to purify the water with a Steripen UV water purifier. The Pre-Filter can be used to fill a water bottle via two direct methods: via Pour Through and via Immersion.