It's generally generic.
In the package of Bluetooth headphones, there is no charger configuration, and the use of usb2.0 standard charging interface interface.
Query its manual, will be marked, charging parameters: 5V1A\/2A can be, and there is no mark the power frequency is 50 or 60 Hertz. Look at the mobile phone charger, it is completely 5V1A or 2A, so it is suitable for charging the Bluetooth headset.
The airpods2 charging case has two models, of which the A1602 is a wired charging case and the A1938 is a wireless charging case.