The built-in battery, there is no running wires for the power supply. The built-in speaker is not bad, but not strong enough for my taste. Therefore, I have a Bluetooth transmitter (with battery) is connected to the headphone output and the sound is played back via a Bluetooth speaker in the desired quality. So all without wires as pitfalls
The projector reproduces almost all popular formats of internal memory, the SD memory card or from a USB stick. Even an external hard drive (3.5 "with its own power supply) with NTFS formatting is detected. However, the USB port of the projector delivers too little power for a 2.5" hard disk (at least for me). Here help continue an active USB hub with power supply. In other words, external hard drives are to be used only with "clutter".
Also the connection of a Samsung Galaxy Note 2 or a notebook via the HDMI connection succeeds immediately. However, the necessary adapters / cables are sold separately.
Conclusion: The small projector is ideal for mobile and spontaneous use. Quick and easily presentations, movies and pictures can also be presented in a larger circle. With some preparation (Dubbing to device, SD card, USB flash drive) no cables are required.