Barton Perreira's Byron eyeglasses are handcrafted of matte tortoiseshell acetate. Handmade. Round shape. Keyhole bridge. Silvertone metal detail at temples. Clear lenses. 49mm eye size. 21mm bridge size. 145mm temple size. Available in Matte Heroine Chic (tortoiseshell acetate). Acetate. Made in Japan. Includes hard protective case and cleaning cloth.