The range depends on the radio system used: for the WLAN connection to the doorbell, practically only the distance to the home WLAN (dual-band Wi-Fi) applies; for the connection between the doorbell and the internal gong/hub, the radio ranges of the integrated hub (Zigbee/thread) and structural influences apply.

Key points for planning:
- The doorbell connects to the home network via Wi-Fi (dual-band); the stable Wi-Fi range up to the house entrance is crucial for live view and notifications. Source: Manufacturer's information on connectivity.
- The integrated gong/hub supports Zigbee and Thread and can serve as a smart home centre; range to Zigbee/Thread devices can be greatly reduced by walls/metal and varies in practice from place to place.
- Practical reports state that the range may be limited in the case of metal doors or heavily shielded environments and that an installation location close to suitable radio permeability should be selected; in one test, a rough guide value of around 10 metres as the crow flies to the main unit location was given (depending on building materials).

If you like, I can recommend the following practical next steps:
- Check with a smartphone at the planned installation location whether your WLAN (2.4 GHz or 5 GHz) is stable there (signal strength/test stream).
- If Wi-Fi is weak: Use a Wi-Fi repeater at an intermediate location or place the doorbell close enough to the router.
- If you are unsure about the Zigbee/threaded connection: Position the router/chime in the house so that there are as few metallic/shielded obstacles as possible between the doorbell and chime.

I am not completely sure about a fixed metre specification in all environments; the available information does not give a binding maximum value for every building situation. If you want, tell me the materials/distances (e.g. distance in metres, wall construction), then I can take a more concrete look at whether the connection is likely to be stable.