Sustain liquid reserves for a longer time between fueling, bite valve tandems with large diameter red colored pipeline tubing for easy efficient delivery. Water is second only to oxygen in importance, never be without it.Take along a Reservoir. Reservoirs details:BPA free, Phthalate free, and PVC freeSlide Seal opens wide for refilling, and seals tightTurns inside out for easy cleaningSimple Plug-N-Play tube attachment5/16th diameter tubing for high flowTubing comes standard in UltraRed