FINE WORKMANSHIP - These 8 turning forks (256Hz, 288Hz, 320Hz, 341.3Hz, 384Hz, 426.6Hz, 480Hz, 512Hz) are made of High-quality alloy , Fine production High accuracy , this ergonomic handle is easy to hold CLEAR SOUND - Delivers clear tone, sound and accurate tuning, can be used for healing, Hearing detection,childrens teaching, stress relieving - Improve learning concentration; Quick send negative emotions, improve insomnia, promote positive energy. INSTRUMENT TUNING - Any instrument which can be tuned but most commonly used with stringed instruments. PACKAGE INCLUDE - A silicone hammer to as a percussion tool, a Hard case storage to protect the tuning fork. Colour:silver Material:aluminum alloy Package Contents: 8 x tuning fork 1 x hammer 1 x wooden box 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.