Measuring 2.25 inches long and weighing just half an ounce, the SMSL IDOL + is one of the smallest DAC/amps around. But dont be fooled by its slim profileit has what it takes to power high-impedance headphones with ease, and sampling rate supports 192kHz. Inside, the IDOL + AMP chip uses MAX97220A. Suitable for most earphones. The exterior is aesthetically pleasing and simple, with a volume control and mute botton on the top panel, a 3.5 -millimeter headphone out on one end, and on the other, a Micro USB port for connecting to your laptop or mobile device.