1. The tuning fork set is made of high-quality aluminum alloy. 2. Compared with the steel tuning fork on the market, the workmanship is more refined, the weight is light, and the corrosion-resistant aluminum alloy structure is durable. 3. The frequency of the tuning fork group is more accurate, and the frequency can reach 25 seconds. A tuning fork set is used for healing. 4.528 Hz is the frequency of love, great for repair, balancing energy centers, enhancing focus, purifying mind and body, also great for sound therapy and playing with pets. 5. Tuning fork set includes 174 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, 639 Hz, 741 Hz, 852 Hz, 963 Hz, rubber base, silicone hammer, cleaning cloth Color: Black Material: aluminum alloy Package Contents: 9 x tuning fork 9 x base 1 x cloth bag 2 x rubber hammer (Random color, don't accept the specified color.) 1 x cleaning cloth Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.