HAND-HAMMERED GONG: Gongs are hand-hammered by a master gong maker, and materials that have gone into crafting gongs for thousands of years. Each Gong comes with a stick & string for hanging A total of three types of treble, midrange and bass TRADITIONAL CRAFT: This Copper Gong is 100% hand made and hand hammered using B20 cast bronze, so each one delivers a rich, authentic sound. MULTI-PURPOSE: The Gong produces a full and sustained wash of musical overtones for healing, meditation practices. GONG SOUNDS: Bao Gongs produce a variety of overtones, from high to low frequencies. Smaller sizes have a higher pitch and less power while the larger sizes are deeper and rich, with a long sustain. Note: Copper reflecting light is strong, the picture of the surface of the copper will produce color difference, uneven, uneven stripes and other phenomena, the actual physical normal phenomenon. Copper used are man-made may have a small error.