Renaming Devices

Apple support's article:

Change the settings of your AirPods and AirPods Pro - Apple Support

says:

"Name your AirPods

1. Open your charging case.
2. With your AirPods in your ears and connected to your iPhone, iPad, or iPod touch, go to Settings > Bluetooth. Alternatively, you can go to Settings > AirPods.
3. Tap the More Info button  next to your AirPods. 
4. Tap the current name.
5. Enter a new name for your AirPods.
6. Tap Done."