Sonoff NSPanel Pro Gen2 3.95″ touch panel with 2 relays, Zigbee and Matter gateway, Dim Gray

Touchscreen diagonal in inches (1 inch = 2.54 cm). Not filled in for models without a touchscreen.

How many lighting circuits or other loads can be wired straight to the panel, as to a regular switch. A panel without relays only controls other devices over the network and goes into a wall box with no load.

The player's platform: it determines the interface, the app store and voice search. Google TV is a newer interface built on Android TV with combined recommendations from different services; the system version is in the note and affects compatibility with new apps.

Whether other apps can be installed on the panel — for example Home Assistant, a browser dashboard or an intercom app. How (app store, manual install) is in the note.

Whether the panel has a speaker and microphones — for sound alerts, voice control or playing audio through a Bluetooth speaker. What the firmware actually supports is in the note.

The number of pixels horizontally and vertically. At the same diagonal, more pixels mean sharper text and video.

The processor, RAM and storage as the manufacturer states them. The amount of RAM affects how smoothly the interface and third-party apps run.

Which device networks the panel runs itself, without a separate hub: Zigbee, Bluetooth Mesh, Thread. 'Matter bridge' passes the panel's devices on to Apple Home, Google Home and Alexa; 'Matter controller' means the panel adds other brands' Matter devices itself.

The wireless link or network the device uses. Wi-Fi connects straight to the router; Zigbee, Thread and Bluetooth Mesh work through a hub or gateway.

Whether the device needs a separate hub, gateway or coordinator to work in a smart home. If so, it is sold separately unless stated otherwise.

How the device connects to Home Assistant: a built-in integration, a Zigbee coordinator, Matter or the maker’s cloud integration.

Whether the device keeps working over the local network or through a hub when the internet is down. Cloud features (remote access, voice assistants) need the internet.

The maker’s app used to set up and control the device.

The highest current one built-in relay handles (resistive load unless stated otherwise). For LED lamps and motors the allowed power is usually lower; the combined limit for all channels is in the note.

Where the device gets its power: 230 V mains, an adapter, USB, batteries or a built-in battery.

The supply voltage (and current, if stated) as the maker gives it. It must match your mains or adapter.

The highest total current through the device per the spec sheet. With several channels, their combined load must stay below it.

Whether the wall box needs a neutral wire. Older wiring often brings only the live wire to the switch; then pick a model that works without N.

How and where it is installed: in a wall box, on a wall or ceiling, on a DIN rail, on a table or in a socket.

Which wall box the panel is designed for, per its documentation. 86 × 86 mm panels fix with screws 60 mm apart, as on a round European box; check that the housing depth fits your box. Wide panels need two boxes or their own back box.

The device’s size in millimetres as the maker states it. Check that it fits the wall box, niche or shelf.

The device’s weight without packaging, per the maker.

Standards and certifications the maker lists for this model (for example CE, RoHS, Zigbee 3.0, Matter).

Sensors inside the panel. A proximity sensor wakes the screen as you approach; a light sensor adjusts brightness; built-in temperature and humidity sensors can be used in automations.

The housing colour of this model. Other colours in the same series are separate products.

The air temperature range the device is rated for. The lower limit matters outdoors, on balconies and in unheated rooms.

The rated relative humidity range, non-condensing.

Total speaker power stated by the maker. It gives an idea of loudness and bass headroom, but the sound also depends on cabinet size and number of drivers.