This is a magical little adapter! But it does have a couple quirks. I recently acquired an Akai MPK Mini Mk3 and I simply wanted to use my iPhone 11 as a lightweight mobile workstation with GarageBand, Bandlab, among other MIDI controller apps and DAWs. While lots of people use these adapters with iPads in recording setups, I'm working on a budget as well as trying to make my setup the most portable and lightweight it can be. This adapter is perfect for the job.I found the secret to this adapter is that having a lightning power source plugged into it will not only charge my iPhone while using a midi controller, but it will also power several other devices via a 4-port USB hub, without the need for a hub that has its own power supply. As far as I can tell, the lightning port on the adapter will only charge the device and will not transmit data or audio. While I would still recommend getting a powered USB hub with it's own AC power supply for very power hungry devices if you intend to use it this way, the lightning connection on this adapter does in my case seem to eliminate the need for a powered hub with an MPK Mini.PLEASE TAKE NOTE: While the audio port works well with headphones and headsets, the one bizarre issue I have is that the audio port ONLY works with a headset or regular stereo headphones, and NOT a stereo aux cable, for whatever reason...? I wanted to use the port as a line out for an amplifier/speakers but it simply would not work at all, I tried multiple 3.5mm cables. The adapter's audio jack itself still works well with headsets, I have confirmed it is a 4 pole TRRS jack for headsets with inline microphone/volume controls, it works with live monitoring in GarageBand. Perhaps I simply received a flawed unit, but having tested the adapter with multiple cables and different speakers and not being able to figure this issue out, I simply ended up purchasing a USB soundcard with two separate TRS stereo audio/mic ports for use with a hub, which works equally as well and is much simpler. Again, the adapter does work well WITH HEADPHONES and otherwise flawlessly, but it doesn't work as a typical line out jack should.