Lightweight and comfortable bone conduction headphones, Bluetooth V5.3 compatible. - Model Name: MicCuff J200 - Bluetooth Version: V5.3 - Communication Distance: Approximately 10m - Weight: Approximately 36g - Battery Capacity: 180mAh - Charging Time: Approximately 50 minutes I bought these intending to use them for work, but they are not compatible with my PC, so I am selling them. I opened the package after purchase, but I have never used them, so I will treat them as new and unused!