Battery life: 4G lasts longer, up to 10 hours of continuous use. Wi-Fi is up to 5 hours.

•If you choose the WiFi version: we suggest using your phone’s personal hotspot for the best experience, it’s typically more stable and faster than crowded public Wi-Fi.

•If you choose the WiFi+4G version: 7-Cal uses a nano SIM, so you can insert your own SIM card (we provide a step-by-step guide).

7-Cal requires a 4G LTE SIM card and is not from an MVNO (virtual carrier).

Some consumer SIM cards restrict data-only or embedded devices, which may cause connection failures even if LTE is supported.

If your SIM card does not connect or you are unsure about compatibility, we recommend using an IoT SIM card, such as Hologram (Global), which is designed for LTE CAT-1 / CAT-4 devices and offers a free SIM card with the highest compatibility.

The 7-Cal WiFi+4G version uses a nano SIM card. You can insert your own SIM card once you receive the device. (We provide a step-by-step guide) You can follow the 4G connection guide to ensure a smooth 4G experience on your 7-Cal device.

If you experience issues connecting to 4G on your 7-Cal device, please follow the steps below to troubleshoot.

1. Check SIM Card Compatibility

Please make sure your SIM card:

• supports 4G LTE (not 2G/3G/5G only).

• is not from an MVNO (virtual carrier).

Many MVNOs restrict IoT or embedded devices or block data-only connections. If the carrier does not fully support 4G LTE for IoT-style devices, the connection may fail.

2. Find Your Carrier’s APN Settings

If your SIM card supports LTE but still cannot connect, you may need to manually set the APN. You can look up your carrier’s APN here: https://apn.how/

Steps:

1. Visit the website.

2. Select your country.

3. Choose your carrier.

4. Locate the APN value.

5. Enter this APN in Setting → Internet → 4G Settings → Custom APN on your 7-Cal.

3. If the Connection Still Fails

Some carriers apply additional restrictions to consumer SIM cards. In such cases, using an IoT SIM card is recommended, as it is designed for embedded devices and offers

higher compatibility.

Recommended Option: Hologram (Global)

• Provides free IoT SIM cards

• Works in many countries and regions

• Designed for LTE CAT-1 / CAT-4 / IoT devices

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.