The Zaphir Blue Moon Chime Sky Blue is a wind chime with eight tones in Blue Moon (winter) tuning. The tones are produced by high-quality piano strings, which are also soldered to a solid metal base and then tuned to the tenth of a millimetre. This is how you get the perfect chords that allow the harmonics to play together when the centered bead makes a circular or random movement. The dimensions of the resonator correspond to the concept of natural equilibrium associated with Leonardo Da Vinci's golden ratio, a crucial reason for the quality of acoustic waves. The resonance tube is made of thin layers of calendered cellulose. The spiral winding of the layers creates a thin cylinder that guarantees a crystal-clear sound.