These bells are cut from scrap iron sheet, folded and hammered cold into shape with no welding and no solder - the joints are locked mechanically. The body is then coated in copper and brass powder with a mud-and-clay paste and fired, which is what gives it the warm colour and the resonance.
Salim Luhar tunes each one by ear after firing, filing the lip until it sits in the right note; the Luhar families of Nirona traditionally made these for herders, who could identify an individual animal by the sound of its bell across the grassland. The thirteen sizes are tuned to sit together, so a cluster of three or four rings as a chord.