The hydration systems allow for a continuous supply of liquid without having to interrupt physical activity. Deuter backpacks are specifically designed to accommodate these hydration systems. The entire system is free from BPA and PFC. Hydration system expertise from Source: Taste-Free: The inner surface of the hydration bladder and the tube is as smooth as glass. Due to these molecular material properties, the Streamer is tasteless, very hygienic, and easy to clean. Grunge-Guard: This coating, which is firmly bonded to the carrier material, prevents the growth of bacteria in the hydration system. Easy Clean: The hydration bladder can be easily filled and cleaned through the large opening across its entire width - completely leak-proof thanks to the slide-clip closure. Dirt Guard: The attachable protective cap keeps dirt away from the mouthpiece during extended transport.