Miui (its not stock Android but give it a chance. They will be fine for light use for running errands, going to the pool etc but I would not want to put many miles on them. I wear them around the house, out to the grocery store, and the navy color is classy. Me llegaron en 4 días después de pedirlo, estoy muy contenta podré dormir con audífonos para escuchar ASMR sin que se me enreden y hacer otras actividades con ellos. no grommet?. My feet are slightly wide and the band across the toe area did not cut into my toes at all. Very happy with the sound and the battery life. This speaker is very easy to use and have around. Best part is that the call is in stereo to cut distractions. Im still keeping it.