The 128 Hz tuning fork (C3 on the piano) is used for a variety of issues. Paramedics and healthcare professionals have used this fork to locate bone fractures. This particular fork increases nitric oxide the most. This is a gas naturally produced in the body. Nitric oxide has many functions in the body. It can act as a messenger between cells, a neurotransmitter, and a hormone. It helps to dilate blood vessels, supports a healthy heart, increases brain power, improves sexual health, increases blood flow, and is particularly effective when placed on the rib heads, sternum, and hip bones. Two tuning forks gently tapped on the knees and held to the ears create a beautiful, sustained low tone that is great for grounding and relaxation. To listen, hold the 128 tuning fork by the handle and gently tap the weights on your knees or a tapping pad. Bring the tuning fork/forks to your ears and adjust the distance according to the tone. Hold one fork about an inch from your left ear and one inch from your right ear. This will create a long sustained tone. Material: Aluminum alloy Color: Silver Package contents: 1 x 128HZ Tuning Fork 1 x Silicone Mallet 1 x Cleaning Cloth 1 x Repair Tool 1 x Storage Bag 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 to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.