Product Features Ultra-lightweight type that feels like you're not wearing anything Achieves amazing weight reduction! It's so light you'll forget you're wearing it, providing a comfortable fit that won't interfere with sports. The wire uses "surgical stainless steel," which is rust-resistant and unlikely to cause allergies. A smart design that combines sporty and stylish. Product Specifications Material: Body: Stainless steel, nylon / Clasp: Aluminum / Internal parts: Urethane Target: Unisex Made in Japan Thank you for viewing.