This is a case-only listing! Thank you for viewing! I run a battery replacement business in Hiroshima! I'm Chika, a repair and electrical specialist (*^^*) This is a new genuine battery that I replaced with a new one (*^^*) It seems there are some unscrupulous businesses out there, and a friend consulted me because their battery failed for the third time. When I disassembled it, I found a cheap, non-genuine battery inside, designed to break down after only a few uses. This is definitely a genuine new battery, so there shouldn't be any problems, but just in case, I'm offering it with a warranty (*^^*) I will also include a warranty card, so you can rest assured (*^^*) I will provide a free one-week warranty, so please feel at ease (*^^*) Extended long-term warranties are also available, so please feel free to contact me (*^^*) I also accept repair requests, so please feel free to consult with me (*^^*) The images are for reference of a beautiful product! There are some minor scratches, but it's generally clean, so please consider it, m(_ _)m I appreciate your kind words! Thanks to you, it's been a huge success, and I'm about to run out of stock! Even if I run out of stock, I'll have more within a week, so I'll keep listing them (*^^*) Please consider it (*^^*) Wireless Noise Canceling Stereo Headset WF-1000XM4 Brand: SONY Wireless Noise Canceling Stereo Headset WF-1000XM4 (B) Black Brand: SONY Wearing style: Separate left and right, completely independent Earphone/Headphone type: Canal type Structure: Sealed type Color: Black Wireless/Wired connection: Wireless Earphone/Headphone features: Noise canceling, Hi-Res, Microphone, External sound capture, Waterproof, Splashproof, Remote control Low-frequency range (Hz): 20 Hz High-frequency range (kHz): 40 kHz Wireless standard: Bluetooth Wireless function: Multi-pairing Bluetooth codec: LDAC, AAC, SBC IP standard (waterproof standard): IPX4 Driving method: Dynamic type Driver size (mm): 6 mm Charging port: USB Type-C Charging time: 1.5 hours Weight (g): 14.6 g Other features... Noise canceling