Usage Tips:Firework Firing System 4CH SmaPower: Receiver: 4 AA batteries; Transmitter: 12v 23A batteryRange: 150 meters (492 feet)The receivers are very economical. They can be used independently. If one fails, the others will continue to operate. This system is expandable. Simply purchase more receivers from the website . The receivers come pre-programed for your convenience however they are reprogrammable. Locate a small hole in the center of the receiver and insert a paperclip or similar object. The receiver will flash then press a corresponding key on the remote. Now the receiver has been paired with the remote.Caution!1. Handle your product with careoid shaking and dropping it.2. Keep the receiver as far from your as possible tooid damage.3. Remove batteries before storage.4. Store your product in a clean dry area from containments.Frequency: 433MHzThis device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.color:As shownMaterial:plasticPackage Contents:1 x receivers1 x transmitterOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.