Ultimate Direction Groove Stereo Hydration Belt Material: [body] PU-coated 70D nylon ripstop, [back panel] MonoRip Mesh Volume: 3L (177cu in) Hydration Compatible: yes, holds two 500-milliliter bottles Pockets: 1 front zippered pocket (fits iPhone 6 Plus), 1 rear-zip pocket Compression: yes, dual-compression waist belt