Nathan triangle hydration waist pak the nathan triangle hydration waist pak is perfect for walkers joggers and runners designed with an adjustable webbing belt with a clip fastening for a secure and comfortable fit this nathan running pack also features a zipped pocket to the side that is perfect for small items and is complete with bpa and pvc free water bottle so you can stay hydrated while on the move running water pack adjustable webbing belt with clip fastening zip pocke