The Nathan Fireball Hydration Vest is an ultralight running vest designed for a distance runner or cyclist with minimalist sensibilities. With two 12 oz. insulated flasks and compatibility with a 1.5L bladder, it keeps you hydrated. Slide adjustable chest strap that enhances fit and reduces bounce while running Weight is balanced using a rear focused storage design, offering comfort and ease of use along with versatility to store gear or additional fluids Mesh shoulder straps wick away moisture for enhanced overall comfort Comes with two 12 oz. insulated SpeedShot Flasks with Push Pull Blast Valves for quick hydration SpeedShot insulated 12 oz. Flasks designed with double wall construction that keeps fluids cooler 20% longer than other insulated bottles 1.5 liter bladder compatible not included Expandable main zippered pocket allows easy access to your gear Front stash pockets with hook and loop closure easily hold several energy gels or other small items Large pill pockets on front for easy, quick access Reflective trim for visibility in low light Gear capacity: 7 liters 427 cubic inches Weight: 13.3 oz.