This product is a wireless multifunction intercom system telephone, able to support 1 to 9999 user in one system, two-way intercom, also hands-free intercom. The device can use 18650 battery, easy loading and unloading, long standby time. It is equipped with a LCD screen, which displays rich content and clear functions instructions. The technology adopts the 433MHz frequency and has good well-penetranting performance. Its wireless communication distance is upto about 1000 meters in open areas.