On the Wi-Fi + 4G version, you can use either Wi-Fi or 4G LTE, depending on what’s available. The system features are the same in both modes. The main differences are connectivity and battery usage. Battery life may vary by network mode. In general, 4G mode can last longer, up to 10 hours of continuous use, while Wi-Fi mode is up to 5 hours. Your actual results may vary depending on signal strength and usage. If you plan to use Wi-Fi mode, we recommend using your phone’s personal hotspot for the best experience, as it is often more stable than crowded public Wi-Fi. If you plan to use 4G mode, 7-Cal is designed to use a nano IoT SIM Card. Please insert your own IoT SIM card (we provide a step-by-step guide on the manual page). Note: If you are comparing product versions, the Wi-Fi version supports Wi-Fi only, while the Wi-Fi + 4G version supports both Wi-Fi and 4G. For full details, please refer to our Tech Specs page.

7-Cal WiFi+4G Version is designed for a 4G IoT SIM card (CAT-1). Some consumer phone SIM cards restrict data-only or embedded devices, which will cause connection failures even if 4G LTE is supported. We recommend using an IoT SIM card, such as Hologram (Global), which is designed for LTE CAT-1 / CAT-4 devices with the highest compatibility. You can also search for your own local IoT SIM Card providers. Based on our testing, some phone SIM cards may also work directly. For example, in the UAE, SIM cards from Etisalat (E&) and Du may work, and in the UK, O2 SIM cards may also work directly.

The 7-Cal WiFi + 4G version is designed to work with a nano 4G IoT SIM card(CAT-1). You can insert your own SIM card after receiving the device. A step-by-step setup guide is provided in the manual. You can follow the 4G connection guide to ensure a smooth 4G experience on your 7-Cal device. For customers in the UAE, based on our testing, phone SIM cards from Etisalat (E&) and Du may also work directly. For customers in the UK, O2 SIM cards may also work directly based on our testing.

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 Card The 7-Cal WiFi+4G version is designed to work with IoT SIM cards. Please make sure your SIM card: is an IoT SIM card supports 4G LTE (not 2G/3G/5G only) & LTE CAT-1 Many 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 Lock Some 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 carrier Remove any PIN or PUK lock from the SIM card through the phone settings SIM cards with PIN protection enabled may prevent the device from connecting to the network. 3. Configure the APN Settings If 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 devices You 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, in the UAE, SIM cards from Etisalat (E&) and Du may work, and in the UK, O2 SIM cards may also work directly.

You can view both the APN and IMEI directly in the 4G Settings on your 7-Cal calculator. These details are useful when configuring a SIM card or contacting your carrier for activation. For step-by-step instructions and additional details, please refer to the user manual.