Moes ZB-TDD9-RCW-MS recessed Zigbee RGBCW downlight 2700–6500K, 9W

The diameter of the ceiling hole the light fits into. A range means the spring clips hold the light in holes of different sizes — handy when replacing old spots. For rectangular lights, see the rectangular cut-out size.

How much free space above the ceiling the light needs. Matters for stretch and suspended ceilings with a small gap and where beams or pipes run above the ceiling.

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

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

How much light the fixture or bulb gives at full brightness, in lumens. As a guide, about 800 lm is roughly what a 60 W incandescent bulb gave. A room is usually lit by several sources, and their flux adds up.

How widely the light spreads. A narrow beam (up to 25°) picks out a single object with a spot; 30–40° gives directed light on a table or wall; 60° and wider gives even light on the floor and general lighting. For the same luminous flux a narrow beam gives a smaller but brighter spot.

What light the fixture can give: one shade of white, tunable white from warm to cool, or colour as well. Tunable white lets you, for example, make the light warm in the evening and neutral during the day.

The range of white shades in kelvin: 2700 K is warm like an incandescent bulb, 4000 K neutral, 5700 K and above cool, close to daylight. If the shade is fixed, both values are the same.

How far the light can be dimmed, as a share of full brightness. The smaller the number, the dimmer it can go at night or during a slow fade: for example, 1% and 0.1% look clearly different in a dark room.

The rated or maximum power draw from the spec sheet. It sets the load on the socket and the energy use.

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

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

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.

Whether the device supports the Matter standard, directly or through a bridge. Matter lets you add it to Apple Home, Google Home, Alexa and Home Assistant.

The coordinator's maximum radio output. Higher power gives a steadier link to distant devices, but range in a home depends more on walls and the number of routers in the network.

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

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

Whether the light can change colour and brightness to the beat of music. A built-in microphone listens to the room by itself; in “via phone microphone” mode the smartphone with the app open must hear the music.

The warranty period the maker states. Confirm warranty terms in Moldova with the seller.