Cotopaxi Alpha X 4L Hip Pack in Rust Butterfly-style opening for easy access Side release buckles for compression Main compartment two-way zipper. Wings can be stowed in the back panel when traveling for easier packing Rounded corners and darts give the front pocket more volume for packing. Fits perfectly inside top pocket of Allpa 35L and 42L TPU-coated 1000D polyester 840D ballistic nylon paneling