Pure Hydration (BW Technologies Limited) is an independent British firm (a rare thing!) that specialise in the development, manufacture, sale and distribution of outdoor water purification systems for the personal, aid and military markets on a global basis. Product production is controlled by the company under a quality system to ISO 9002 standards. Manufacturing activities operate to ISO 9000/9001 standards. The company has a long experience in creating filtration systems. So why choose PH over the mixture of usual suspects? Well its down to trust and quality of there product, there hydration systems are built to last and have been tested and Endorsed by the Hospital for Tropical Diseases The in line filter system can be fitted to any existing water reservoir but to be honest there packs are second to none.