The Mixcder HD901 headphones cover just enough of my ears to provide isolation from noise but I don't feel occluded from the world as is the case with in-ear buds. I am able to hear people talking around me as well. Plus the HD901s are so lightweight (141-grams) and they don't clamp on my head like I'm use to with studio headphones. The drivers are 40-mm in diameter and headphones have 20-Hz to 20-kHz frequency response and will make up to 108dB SPL with plenty of bass!

After charging them up (takes 2 hours) with the included USB cable plugged into the Micro USB slot, I was ready for up 8 hours of playing time with 2,000 hours of standby time. Besides the built-in battery, on/off switch and microphone, there are buttons for up/down volume, and a TF memory card slot for playing already recorded MP3s.

The headphones "paired up" nearly instantly up to 33-feet away with my iPhone X and I like the confirmation of pairing and powering up/down and when I reached max volume.

The Mixcder HD901 Headphones are designed to travel with a fold-up design that I liked for throwing into my backpack when walking to school. They come with a wired headphone cable and do not use any battery power when wired in.

I like these little guys a lot and the most amazing thing is that Mixcder HD901 Headphones sell for $19.99 and have a 1-year warranty!

Totally recommended!