1. Small palm size of receiver for mobile usage 2. 2.5" LCD screen with 480 x234 resolution 3. Rechargeable Li-battery in receiver, enable at least 2 hours continuous working 4. Built-in rechargeable Li-battery in camera, for at least 5 hours continuous working 5.380TV lines clear picture display 6. Built-in microphone in camera and speaker in receiver 7. 4-channel available to avoid interference 8. Min. 100m transmission distance without black 9. Rechargeable Li-battery which built in camera 10. Built-in Li-battery in camera 11. Both Video and Audio Monitoring. The product builds in 1/3" CMOS image sensor and microphone, provides 300K pixels high quality display and high sensitive audio monitoring. 12. The product works on the license-exempt 2.4GHz industrial, scientific, and medical(ISM) frequency band.