BPA-free bladder with an easy clean, big bore top.Pack harness is angled away from the underarms giving total freedom of movement.Harness made with air mesh for ventilation.Neoprene hydration tube sleeve helps keep fluid cool.Magnetic bite valve holder.Large main compartment and secondary compartment with internal mesh pockets for organization.Straps on front to cinch down additional luggage.Reverse face YKK® water resistant zip on front.Thermal lined bladder compartment helps keep fluids cool.