Our 40 MM audio earphone speaker,headphone speaker,moblie phone speaker,Bluetooth Speaker are high output,high sensitivity Product Name: High quality 40 MM audio speakerModel No:SPK-20MSSpeaker Size: 20mmImpedance: 32ΩRating power: 20MW40 MM audio earphone speakerWe can produce different size of the earphone, aslo can OEM as your detailed need. High quality 20MM audio speaker with wire attached