The 10.8 litre capacity UD Ultra Vest 5.0 features increased adjustability with UD's updated Comfort Cinch™ 2.0 technology system providing a customised fit with quick fine-adjustment whilst running. With five rear storage pockets/compartments, the bladder compartment can accommodate up to a 2 litre reservoir. 4-way stretch fabrics maximize storage, stabilise contents, eliminate bounce to reduce chance of rubbing, irritation and chafing, and increase abrasion resistance and durability. Trekking pole holsters hold z-poles firmly in place, minimizing bounce and snapping out of the way when not in use. A safety whistle is included as well as two updated Body Bottle III 500 soft bottles. Large reflective logos for high visibility in the dark from the front and rear.