Like other reviews mentioned volume is low.

In our 2017 Chrysler Pacifica the volume was barely audible even when turned up all the way

While all 4 units do work, the volume is very low and the reception is very poor (on both channels).

Super low volume even when set to high volume

Build quality is ok, but the sound pops and cracks constantly on both set and volume is not loud enough

Unfortunately, the ear padding in the headphones didn't keep out any outside noise, and the volume was not enough to compensate enough for the kids to be able to hear the movie while adults talked in the front seat

The volume was perfect for kid's ears but needed to be little louder for adults