Source Clear 1.5 Litre 2009 New and updated for 2009 featuring; Quick release baldder tube Wide filling neck NEW Locking Helix bite valve will not drip even under pressure Dust and dirt bite valve cap Strong carry handle Source bladders are: Taste-Free A high tech co-extruded film & tube retains pure liquid taste with no plastic flavor. Bacteria-Free Grunge-Guard - Anti-microbial technology blocks bacteria growth for the life of the system. Glass-Like Liner technology prevents bio-film build-up, system is self-cleaning. Atomic Force Microscope (AFM) surface analysis shows that Source�s Glass-Like film is 1000% smoother then that of competitors using PU films with only a 50% difference from glass itself. Care-Free Glass-Like technology combined with Grunge-Guard technology represent a new generation in hydration system where cleaning is no longer an issue. Simply refill and drink again and again without special care. The same water will remain fresh for days and even weeks.