The 1L hydration bladder is made from durable and safe TPU material. It fits perfectly in your hydration compatible sling/fanny pack. It fits in the sling's hydration compartment and the tube routes through the included hydration port of your pack. It includes a locking bite valve so you don't get water where you don't want it. 

It is BPA free and approved by the FDA, EZ-71, and LFGB.