Features:Wireless intercom system, no telephone wires needed, save your phone bills.Clear Voice and Secure Digital Communication. 433MHz working frequency, anti-interference signal. It needs no installation nor an installer, simply plug and use.Built-in rechargeable battery, works with or without electricity power, standby time 30 days.Long communication distance up to 500m(depending on the environment).Can be placed on desk or mounted on any surface, horizontally on wall surface or vertically on any flat surface.A wireless intercom system can be a convenient way to communicate throughout your house, office or warehouse.This Plug & Play Wireless Intercom is very simple to use, clear two way communication and has an impressive 100 meters within building and 500 meters in the open field without barrier transmission.Specification:Standby Current: 800AWorking Current: 400mACharging Current: 230mAWorking Frequency: 433MHzTransmission Rate: 256KPower Supply: DC 5VRemovable Battery: 3.7V 18650Size: Approx. 217 x 112 x 70mm/8.5 x 4.4 x 2.8inch Application: Widely used in homes, offices, warehouses, workshopsOperating Instructions:1. Simply plug and play2. The intercoms ID code had been set. the ID code is listed on the top right corner of intercom.3. Full charged the intercom to power socket directly, turn on switch at the bottom.4. Dial the ID number(1, 2, 3) for which you want to call and press call button, the called intercom will rings, pick up and answer the call.Package list:1 x Wireless Walkie Talkie1 x Data Cable1 x User Manual.Note:Please notethat the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.