... batterys life. USB1.1 interface, plug and play, automatically code study and easy to use. Pretty small receiver, Human Factor ... low level emission, which is green, health and environment protecting.Tech-Specification Frequency: 315MHz/433MHzOperation range: 20meters Laser wavelength: 660 ... Up or Down smoothly, the receiverll flash ,it means the code-study is successful. At this time, Receiver & Laser ...