SMSL i2 is a mini portable DAC and headphone amplifier with lightning port input, 3.5mm stereo headphone jack output. Designed for iphone7/7plus and also compatible with other Lightning port-equipped devices. Powered by Apple devices,metallic housing design,built-in microphone,with volume control button and mute mode botton,more convenient for operation. With Apple MFi Certificated, compatible with all Apple-supported music playback software. Recommend 'SMSL player' for best sound effect,supports music formats DSD64-128dsf)/WAV(44.1-384kHz)/APE/FLAC/AAC/MP3