Product Details Run fast, filter faster. The UltraFlask+ Filter Cap threads seamless onto all of HydraPak’s 42mm running flasks and handhelds for a lightweight, straightforward filtration solution. Featuring a traditional bite valve and cap design, runners can drink freshly filtered water directly through the high-flow Blaster valve. FILTER FACT SHEET | FILTER USER MANUAL *Effectively removes common waterborne bacteria, such as E.coli (99.999%) and parasitic cysts (99.9999%) per HSF 42. Beyond Lifetime Guarantee Easy To Use High Flow Lightweight And Compact Weight: 36 g / 1.3 oz Dimensions: 42mm Material: ABS, POM, Silicone, Hollow Fiber Care: Avoid freezing filter. Freezing may ruin the hollow fiber membrane. If in freezing conditions we recommend you keep the filter in your pocket or near your body to prevent freezing. Features FAST & SAFE FILTRATION The integrated filter removes Escherichia coli bacteria, Cryptosporidium parvum cysts, and Giardia Lamblia from approximately 1,500 liters of water at a rate of >1L per minute.* INCLUDED BACKFLUSH ADAPTER Plugs into filter valve and threads onto a HydraPak Stow or bottle of clean water for backflushing the filter to restore its flow rate. LIGHT AND COMPACT Minimal design and lightweight materials make this filter the ideal choice for runners. It takes up no extra space when stored or threaded directly onto a flask. HIGH-FLOW Easy to drink bite valve auto-seals after each sip, eliminating annoying drips. 42MM THREAD COMPATIBLE Easily thread the filter onto some of the most popular running softflasks, flexible bottles and water storage containers.