Osprey’s Hydraulics® LT 1. 5L Lumbar Reservoir by Hydrapak is made for those who prefer an off-the-shoulder hydration solution. Designed to fit in most lumbar packs, but perfectly pairs as an extra or replacement reservoir for Osprey's Seral lumbar mountain biking pack. Twin-welded chevron baffles stabilize the water and maintain a flat profile. Thoughtful design makes filling, cleaning, and—most importantly—staying hydrated on the trail easier than ever. All parts are BPA-free, phthalate-free, lead-free, guaranteed. All materials are certified food safe according to FDA and EU regulations.