A fly case that allows you to pass the tippet through the hook eye without removing the threader on which the fly is set. Just raise the threader holder, pass the tippet thrugh the threader, and pull out the fly. BY adding each spare threader (sold separately), you can carry mroe types of flies. System Foam can be detached and replaced with other System Foam inserts available. Color: Off White Model Dimention(W×H×D) Weight SKU Large Threader Fly Case 197×42×114(mm) - 7.76x1.65x4.49in 252.5g CF-3610THR+ Medium Threader Fly Case 155×40×105(mm) - 6.1x1.57x4.13in 174.5g CF-2610THR+ Small Threader Fly Case 130×36.5×104(mm) - 5.12x1.44x4.09in 148g CF-1610THR+ 5 types of threaders are included, 2 each, 10 in total. Long (standard) x 2 Long (midge) x 2 Short (standard) x 2 Short (midge) x 2 Short (ultra midge) x 2