The Craig Electronics stereo headphone also features a speaker to play all audio devices through 3.5mm built-in aux in cable. Speaker features a max power of 8 ohm, 0.5W X 2 and volume control for speaker. DC Operation for speaker 2 X AAA batteries (not included). Input Plug : OD3.5mm Nickel-plated straight pin. Compatible with MP3, iPod, iPad, iPhone & Smartphone.