The interest of a DAC is that it is able to reproduce the sound of the highest quality for tat "HiFi" well above that offer integrated computer sound cards. So if you want to listen in the best digital music quality speaker DAC is highly recommended.
This model has the advantage of being efficient, widely recognized by connoisseurs, and it is quite affordable: a competitor and as versatile product costs at least twice ...
Its low cost is explained by a conception keeping only the essentials as well as a minimalist presentation, far from the luxury codes of products called "audiophile".
This is a small basic black plastic casing, delivered in a simple bubble envelope, no box or instructions. This being the reference is unnecessary because it works directly on most systems: Windows, Linux and Mac but also so Raspberry (personally I use it with piCorePlayer)
This DAC has a 3.5mm output (note that on the one received it's black and not blue as in the photo) that allows direct connection headphones or an amplifier with a classic line input. This output jack is also an optical output for use with an optical cable 3.5mm. No adjustment is necessary, the DAC will automatically detect the connected device and adjust accordingly.
In conclusion this DAC is a very good investment for those who are primarily concerned with the quality of listening, and the design and packaging unnecessarily flattering leave indifferent.