C&F THREADER FLY BOX STANDARD #CF101 Famous Threader Fly Boxes for fly fishers having problems poking a tippet through a tiny hook-eye. Boxes have THREADER-LOADERS BUILT-IN. You can pre-load the flies (sizes #12 thru #18) on the threaders before you head for the stream. When you open the fly box on the stream, the fly-loaded threaders stick straight up, waiting for the end of the tippet. Simply poke the tippet through the threader, and SHAZAM, the tippet is loaded through the hook-eye automatically. Boxes weigh nothing. 3 3/4" W x 5" H x 1 1/4" D.