Thank you for viewing this item. These are wireless Bluetooth earphones. I have used them a few times. They are currently working without any problems. The replacement ear pads and USB cable are unused. This model does not have an app for sound quality control, etc. I think it would be good if the player side had something that could be operated. It is still a clean item, but it is a used item, so please understand and consider it. --- Tama Electric Industry Nyan-ko Sensei Complete Wireless Earphones Natsume's Book of Friends Bluetooth 5.3 AAC Compatible Call OK Touch Sensor IPX4 Water Resistant NTM-BS75 Series (White) Bluetooth Earphone Section Model Name: BS75 Communication Method: Bluetooth 5.3 Maximum Communication Distance: Approximately 10m (Class 2) in clear sight Compatible Profiles: HFP/A2DP/AVRCP Supported Codecs: SBC/AAC Pairing: Maximum pairing registration of 8 devices Passkey (Authentication Code): 0000 (four zeros) Built-in Battery: Lithium-ion polymer battery Built-in Battery Capacity: 40mAh Charging Time: Approximately 1.5 hours * Continuous Communication Time: Approximately 3.5 hours * Maximum Music Playback Time: Approximately 5 hours * Size (per side): Approximately W15.8 x H20 x D26.3mm Weight (per side): Approximately 3.5g Waterproof Level: IPX4 Material: ABS, etc. [Charging Cradle Section] Built-in Battery: Lithium-ion polymer battery Built-in Battery Capacity: 300mAh Rated Voltage: 3.7V Power: 1.11Wh Charging Time: Approximately 2 hours * Number of Earphone Charges: Up to 2 times * Size: Approximately W47.6 x H30.5 x D47.6mm Weight: Approximately 31g Material: ABS, etc. [Charging Cable] USB Terminal: USB-A connector / USB-C Cable Length: Approximately 30cm Cable Rating: DC5V/2.1A Weight: Approximately 12g Material: PVC, etc.