A3047, A3048, A3049 Compatibility: The earbud is compatible with Pro2nd and works with original charging case. Important Compatibility Notes: Incompatible with charging case: A2700, earbuds A2931, A2698, and A2699 Convenient Charging Feature: Pre-charge the A2968 charging case, and you'll have a portable power source for the earbud during outings without access to electricity, ensuring continuous audio enjoyment. Quality Assurance: Although used, this earbud adheres to OEM standards, delivering the same high quality and performance as the original. It’s a reliable and cost-effective replacement solution. Pairing Guide: Remove existing earbud connections from your device's Bluetooth list. Charge the earbud for at least 30 minutes with your iPhone/iPad placed right next to it. Reset the earbud and re-establish the Bluetooth connection. If pairing fails, extend the charging time, preferably overnight. Encountering issues? Reach out to us. Note that the pairing process might take longer—patience is key!