Its design allows anglers to separate different sizes and types of flies, split shot, indicators, floatants, etc. and then easily resupply each individual cup when needed. Fly tyers are already utilizing the JamPac as a tying bench organizer for hooks, beads, materials, etc. and even as a travel kit. This is an awesome organizer for guides, shops and fly tyers. It holds 20 of New Phase's exclusive fly cups, including 8 standard cups with tethered lids, eight divided cups with tethered lids and 4 midge cups with removable lids. all cups nest tightly into the high density foam liner.