Umpqua designed the Ambi-Sling ZS to fit over left or right shoulders comfortably, and it holds enough fishing gear for a full day's adventure. Its main compartment holds four large fly boxes, and there are external mesh pockets for tons of tippets. Umpqua's Zero Sweep foam gives convenient storage for nipper pots, tools, and various flies. There are also easy-to-access pockets for water bottles and layers.