The 2L Reservoir is made from an FDA approved BPA free Polyurethane material.  This material allows the reservoir to be flexible an puncture resistant.  The UltraRed hose connects/disconnects quickly and features a high flow bite valve.  The top slider allows the bladder to be filled easier and hold more water.  For cleaning and drying, the top slider also allows the reservoir to be turned inside out.  RF welds mold the polyurethane together as if it were one piece to prevent any leaks.