If you experience issues connecting to 4G on your 7-Cal device, please follow the steps below to troubleshoot. 1. Use a Compatible IoT SIM CardThe 7-Cal WiFi+4G version is designed to work with IoT SIM cards. Please make sure your SIM card:is an IoT SIM cardsupports 4G LTE (not 2G/3G/5G only) & LTE CAT-1Many standard consumer SIM cards restrict usage in embedded or IoT devices, which may prevent the device from connecting to the network. If your SIM card is not specifically designed for IoT use, the connection may fail.2. Activate the SIM Card and Remove PIN LockSome IoT SIM cards must be activated first using a smartphone before they can be used in embedded devices. Please check the following before inserting the SIM card into the device:Activate the SIM card using a mobile phone if required by the carrierRemove any PIN or PUK lock from the SIM card through the phone settingsSIM cards with PIN protection enabled may prevent the device from connecting to the network.3. Configure the APN SettingsIf your SIM card still cannot connect, you may need to set the APN manually. You can look up your carrier’s APN here: https://apn.how/ Steps:Visit the website.Select your country.Choose your carrier.Locate the APN value.Enter this APN in Settings → Internet → 4G Settings → Custom APN on your 7-Cal. If 4G connection fails or the device crashes during connection, the SIM card may not be configured correctly. Please insert the SIM card into a mobile phone, set the correct APN, enable data roaming, and confirm that the phone can connect to the network. Then reinsert the SIM card into the 7-Cal and try again. Recommended Option: Hologram (Global) • Provides IoT SIM cards• Works in many countries and regions• Designed for LTE CAT-1 / CAT-4 / IoT devicesYou may use Hologram or any other local IoT SIM card provider in your region, as long as the SIM supports 4G LTE (LTE CAT-1) connectivity for IoT devices. Based on our testing, some phone SIM cards may also work directly. For example:Israel: Partner SIM cards may work.Singapore: SIMBA SIM card may work.Spain: DIGI SIM cards may work.UAE: SIM cards from Etisalat (e&) and du may work.UK: FlexiFone and O2 SIM cards may work.