These cord ends are 304 grade stainless surgical steel, resist rust, tarnish and corrosion. Great easy way to finish off thicker cording necklaces, bracelets, anklets etc. Simply insert the end of your design and pinch the last coil to grip onto your cording. They measure 12mm (1/2 inch) long, including loop and will accomodate cording up to 3mm thick. Package of 20.