3.5 mm
Sound Plug: Retro telephone headset has a 3.5 mm sound plug, which is compatible with various smartphones on the market.
^^ Sound Switch: Retro telephone receiver has an sound switch to further improve compatibility with different brands of smartphones.
^^ One Touch: Cell phones handsets have a one touch answer, press to answer or ring off the phone.
^^ Stable Perfromance: Cell phones handsets feature retro, reduced cell phone radiation, and superior sound quality. 9 feet coiled cord for added flexibility.
^^ Volume Control: Mobile phone telephone receiver has cell phone volume control, slide to adjust the listening volume.