No registration intercom: After receiving the product, you don't need to do any additional operation, just turn on the product and wait for 2 minutes, then you can use the 4G POC network function to intercom nationwide (including SIM card). Unlimited Range Walkie-Talkie: This device operates via 4G networks, enabling real-time unlimited range communication with single calls lasting over 30 seconds. Even without signal, it supports short-range analog walkie-talkie mode, offering 1-2 miles of coverage in outdoor environments. 4G POC Network: This POC walkie-talkie can use network signal. When you travel outdoors, you can very easily communicate with your friends who are farther away. The POC radio comes with a re-paid sim card (1 year limited), and POC account usage fees for lifetime. After 1 Year, you can renew the sim card on KSUN website by yourself. Notice: If you purchase more than 2 units, please send us the group name (such as, "amzct012")via Message. We will help you to put all the devices in a group so that you can intercom. 2 x KSUN CT58