Used single airpod, nothing else, tested working and sanitized

1 airpod only, you must have:

The Airpod 4 ANC case

The other Airpod 4 (ANC Only, a3055 and a3056) will not pair with non-ANC (a3050 and a3053)

1. Put both AirPods in your charging case and close the lid.

2. Connect the case to power (keeping the lid close), and charge for about 1 hour.

3. Open the lid of your charging case (with your AirPods in the charging case), double-tap the front of the case while the status light is on, double-tap again when the status light flashes white, then double-tap a third time when the status light flashes faster. When the status light flashes amber then flashes white, your AirPods are ready to connect to your device.

4. To reconnect your AirPods: With your AirPods in their charging case and the lid open, place your AirPods close to your device, then follow the steps on your device's screen.

Video for Factory Reset : (you have to do it, when you get new replacement Airpods 4)

https://www.youtube.com/watch?v=9CC9yfBmecU