Model Number: YU-RF1009-----1 Key Specifications/Special Features: Features:2.4GHz transmission even carries through ceilings and walls Powerful 864MHz FM signal transmission even carries through ceilings and walls Headphone with integrated rechargeable Li-ion batteries (optional) Base station serves as charger and features 4 selectable FM transmission channels, can also be operated via standard batteriesFunctions:

Wireless/wired headphone

FM radio

Wireless chat online

Can connect directly with TV, PC, DVD, VCD, MP3/MP4 audio source

Specifications:

Frequency range: 2.4 to 2.5GHz

Frequency response: 20 to 20,000Hz

Modulation mode: GMSK

Separation: >70dB

S/N: 95dB

Dynamic range: 88dB

THD: ≤0.5%

Receive sensitivity: -83dBm

Transmission range: 50 meters (without interference)

Driver unit: 40mm

Warm tips:

Do not turn-on at full volume or it'll destroy the headphones easily

Under normal conditions, the volume shouldn't be over 2/3 of the highest volume

To avoid destroying, people should take it off when sleeping

Expert suggest that the adults use the headphone should be less over 3 to 4 hours, and the teenagers should be less than 1 to 2 hours, because their sense of hearing are not mature enough

Spend less time, low-volume to prevent hearing from damage