... 1.Material: Titanium, germanium, magnetic&anion medical silicone 2.Any colors &sizes Silicone rubber Titanium necklaceMaterial: Made of Titanium, germanium, ... cervical for 14-22 degrees, provide negative ions, increase air with oxygen and promote sleep.Features of products: ... neck and shoulders, ease the physical and mental, Increase the body's energy transmission and improve strength, endurance ...