The 500 ml insulated soft flask keeps your water cold twice as long as a normal bottle but without the extra bulk the soft collapsible flask moulds to your hand and the stretchy elastic straps keep it secure even when your grip is relaxed the flask is surrounded by lightweight mesh and features a secure zipped pocket for your phone card or keys specifications collection running activity run user unisex hydration capacity 500ml17 fl oz hydration type quick stowtrade chilltrade fl