This nickel tension bolo back is suitable for any type of cord up to 5mm—it is ideal for leather cord, as it will not mar the leather, or for heavy bolo designs. The spring lever puts tension on the cord, holding it against the bolo back. Squeeze the lever to release tension so that the back can be moved or adjusted without rubbing or scraping against the cord. Solder your designs onto the front panel with low-temperature solder such as Stay-Brite or attach with a jeweler's adhesive such as E-6000. Alternatively the holes on the front can be used to attach designs by riveting or swedging.