Miniwell Gravity Water Filter Straw: Tuv Proven Emergency Kit Hurricane Storm FILTERING MORE - Filters up to 2000 litres of natural fresh water without using any chemicals. 2000L clean and drinkable water in the backpack on the go. GRAVITY WORK - Take use of gravity for filtration. Threads on filter both sides. The whole filtration system can be connected inline. Set up and hang it on the tree. The filtration process is automatic without watching. BACKFLUSHING WITH EASE - Water filter lifespan can be extended by clean water backwash. Inverting clean water collapsible bottle (supplied) can backwash the filter immediately. A syringe for backflush is needless. ENDURABLE WATER BLADDER - Food-grade premium quality materials. The water bladder passed the pneumatic pressure test. Slidelock design reservoir with a wide-mouth opening for fast, easy filling. Convenient and comfortable carry handle. It is not a laundry bag as other brands used. ULTRA-LIGHT AND VERSATILE - L630 water filter can be screwed on 28mm thread disposable bottle. The entire system weighs 0.8 pounds. BUY WITH CONFIDENCE: Lifetime guarantee.