Nathan SpeedDraw Plus Insulated Flask 18 oz/535 ml double wall insulated and hi-viz reflective Speed Draw Flask with Race Cap offers quick bursts of fluid and keeps liquids cooler longer Fully adjustable hand strap with thumbhole enables grip free running Large expandable zippered pocket carries phone, keys, ID and other running essentials First ever 18 oz double wall insulated flask Integrated reflective fabric offers 360 degree reflectivity for visibility in low light conditions