The water-resistant (drip-proof) specification of this product applies only to the headphones, not the charging case.
Although the headphones have water-resistant (drip-proof) capabilities equivalent to IPX4, the part where the sound comes from is not water-resistant (drip-proof).
The water-resistant (drip-proof) performance is designed to protect the headphones if they get wet from rain, etc. (equivalent to IPX4). JIS/IEC protection grade IPX4 means that the product is protected against exposure to flying water from all directions.
The headphones cannot be used underwater.
The headphones cannot be used in hot and humid places, such as bathrooms.
The headphones are not waterproof. Submerging them in water may cause damage.
The headphones may not function properly if they become wet. Wipe the headphones with a dry cloth, shake them multiple times to remove any excess water, and allow the headphones to dry thoroughly before use.