Device idea: a dumb modern #mp3 player.

It would have:
- removable SD card for storage
- USB-C to connect to a computer
- 3.5mm audio jack
- Bluetooth to connect wireless headphones
- Long-lived rechargeable battery

It would not have:
- an app
- GPS
- network
- streaming service integration

It should just be a dumb device with some modern compatibility. Extra points if it had a nice design

I’d buy one directly