Brass base, color cover, 16holes double side two tone harmonica Part number: 11HM017 Brass base, chrome cover, 16holes double side two tone harmonica Part number: 11HM018 Aluminum base, color cover, 16holes double side two tone harmonica Part number: 11HM019 Aluminum base, chrome cover, 16holes double side two tone harmonica Part number: 11HM020