Patented filter technology uses no chemicals to treat water. Supplied with insulating carrier and fully adjustable lanyard - enables use without removing from carrier. Easy to use to drink safe water and also fill other bottles,cooking , flush wounds safely. Instruction guide supplied . Removable replaceable filter cartridge with inbuilt field serviceable sediment filter. System can also be used without filter where water quality assured - simple adaptor tube supplied. Features 'Autoshutdown' when filter life expectancy reached. Ultralight system supplies water on demand at over 300 ml minute - Bottle capacity 800 ml. Can be used stored and reused until 'Autoshutsdown' Filter technology tested UK by Environment Agency (NLS) for removal of waterborne pathogen including virus and anthrax , cryptosporidium, E-Coli and others. Over 4m systems supplied around the world top peacekeeping forces including Red Cross. 75,000 units supplied to Haiti Relief. 1 year no quibble warranty and excellent after sales support.