RoguePak Hydration System Water Storage Bladder, Self-Sealing, BPA-Free and Phthalate-Free Water Bladder - Fits Most Backpacks and Hydration Pack Sleeves (4 Reservoirs) Reservoirs are durable, so you can fill them with your choice of drink and use them as long as you want. Hydration System Water Storage Bladder, designed to fit most bladder backpacks, running backpacks and modular reservoir backpacks Designed with a large self-sealing port, making them easy to fill and even add ice. Great for using to filter water and fits inline filters Economical, so when you decide your hydration system has had enough use, you can afford to replace it with a new one. Compact for convenient use 100% recyclable-NO need to cut any parts off water storage bag- used reservoirs may be recycled into many types of new products All water bladders are made in USA with FDA, USDA and Kosher compliant resin. Available in 50, 70 and 100-ounce sizes to meet your needs