Lefant M210 Pro Omni

Suction in pascal, as the maker measures it. More pascal helps on carpet, but it says little about how well the robot picks grit off a hard floor.

A brush that guides hair to the side instead of letting it wind around the shaft. It saves the cutting work in homes with long hair or pets.

How the mop is built: flat pads, two spinning discs or a roller. Discs press harder on dried-on dirt, a roller rinses itself while it works.

The robot returns to the dock during a run to rinse the mop, instead of pushing dirty water around.

The dock collects dust in a bin instead of a disposable bag. No bags to buy, but you empty it yourself.

The dock washes the mop for you, so you do not rinse it by hand.

The dock dries the mop afterwards, so it does not sit there wet and start to smell.

How the robot maps your home and follows that map. Lidar measures with a laser and works in the dark, a camera looks along and recognises more.

The highest threshold the robot takes, as the maker states it. Measure your own: the step into a bathroom or onto a balcony is often higher.

How tall the robot is. It decides whether it fits under your sofa, bed or cabinet.

How wide the robot is. Narrower gets between chair legs more easily, wider usually means a bigger dust bin.

How much dust the robot holds before you empty it. It matters less with an auto-empty dock, which empties the bin after every run.

How long the robot cleans on one charge, at its quietest setting. After that it recharges and carries on where it stopped.

Which voice assistants the robot works with, such as Google Assistant or Alexa.