Needle keepers are essentially sewing kits. They are made form 5/8" diameter titanium and have a threaded brass cap to hold the sewing needles inside a machined space inside the long axis of the piece. The space is 2.5" long and can hold a number of needles. I wind each one with 20lb test and 200lb test kevlar thread/cord. Each one is made one at a time, all hand machined. They cost $95 a piece.