It has two large wheels at the back, which drive and steer the robot, and a smaller coaster at the front that keeps the base off the ground.
On the top of the robot is a large red stop button and a control panel, consisting of a monochrome LCD screen and four membrane-style buttons. There’s also a rain sensor on the top that, if it detects moisture, will stop the mower from heading out or send it home if it’s already started.
The left side of the mower has a dial for setting the height of the cutting blade, which can be adjusted in 10mm increments between 20mm and 50mm. The right side is reserved for the charging contacts, which connect to extending arms that reach out from the supplied base station.
This side-charging arrangement is unusual but all Worx’s robot mowers use it. It’s a good system, because it lets the mower roll on and off the base plate from either side, keeping the connection tower as close to the edge of the lawn as possible. The upshot is you don’t get an overgrown area inside the perimeter that the mower can’t access.
Although the only way to charge the S400 is by docking the mower, the 20v battery is easily removable from a door at the rear. It’s a standard Worx battery design that can be used across the company’s range of power tools and it can be charged outside the mower if you have a separate charger.
Also included in the box are the various bits and bobs you’ll need to connect the device. These include the cabling you’ll need to connect the charging station to an outdoor three-pin socket, 100m of perimeter wire, a load of pegs to secure it to the ground and a handful of spare parts (replacement blades and wire repair connectors).
