Edge Seamless O-Ring Gag is made using cowhide leather with comfort lining. Nickel free metal hardware. Interchangeable 1.5 inches O-Ring can be replaced with other O-Rings. Lockable buckle closure with 24 inches leather strap. Materials: cowhide leather, nickel free metal. Includes: 1 interchangeable O-gag 1.5 inches, lockable with 24 inches leather strap.