ULTIMATE DIRECTIONA(R) ULTRA VEST 4.0 :: Yes, you can take it with you: your water, your phone, even your trekking poles, thanks to the Ultimate Direction Ultra Vest 4.0. Your newest version of the "best selling running vest in the world" by Ultimate Direction is the lightest yet and includes 2 Body Bottle 500 collapsible water bottles. Your new Ultra Vest is also compatible with a 2L reservoir (not included) for extra hydration on your longest adventures. Stay light cuz the whole pack weighs just 6.7 ounces and features custom-fit cinch straps for on-the-go adjustments.