Yard Force MB400 Robotic Lawn Mower (Black, Up To 400m²)

What size garden is the Yard Force MB400 suitable for?

The MB400 is rated for gardens up to 400m². That's roughly a 20m x 20m plot. It's aimed squarely at small to medium UK gardens. If your lawn is significantly larger than 400m² this mower will struggle to keep up with growth and you'd need a higher-capacity model.

Does it need a boundary wire?

Yes. Like most robotic mowers in this price bracket the MB400 uses a boundary wire system to define the mowing area. You lay the wire around the perimeter of your lawn and the mower stays within it. Installation takes time but it's a one-off job. One customer review noted that the guide wire cannot be placed near power sources so plan your layout carefully before installation.

How steep a slope can it handle?

The MB400 is rated to handle slopes up to 30%. To put that in context 30% is roughly a 17-degree incline. That covers most typical garden gradients in the UK. If your garden has very steep banks steeper than this the mower may struggle to maintain traction or could trigger its tilt sensor and stop.

How does the Bluetooth app work?

You connect to the mower via Bluetooth using the companion app on your smartphone. From there you can set mowing schedules choosing specific days and times. It's worth noting that Bluetooth has a limited range compared to Wi-Fi so you'll need to be within range of the mower to connect. One customer review mentioned the app sometimes displays a "check internet" message so it's worth checking app compatibility with your device before purchasing.

What cutting heights are available?

The MB400 offers 36 manual height positions between 20mm and 55mm. Adjustment is done manually on the mower itself rather than through the app. 20mm gives a short formal lawn finish. 55mm is better suited to longer grass or during dry weather when cutting too short can stress the turf. Having 36 positions gives considerably more precision than many comparable models.

Does it cut in the rain?

The MB400 does not have a confirmed rain sensor listed in its official specifications. One customer review specifically noted that the rain sensor appeared non-functional on their unit. It's advisable not to rely on automatic rain detection with this model. You can use the app to manually schedule mowing around weather forecasts instead.

How many blades does it have and does it collect clippings?

The MB400 uses 3 cutting blades. It does not collect grass clippings in a box. Instead it mulches the clippings finely and deposits them back onto the lawn. This is standard practice for robotic mowers. The fine clippings decompose quickly and act as a natural fertiliser. One customer review noted the grass looked noticeably good as a result of the mulching effect.

What are the dimensions and weight of the mower?

The MB400 measures 44cm in height, 20.6cm wide and 38.4cm deep. It weighs 8.2kg. It's a compact unit which helps it navigate tighter garden spaces. However one customer review pointed out it cannot pass through gaps narrower than 2 metres between structures such as a shed and a house wall. Bear this in mind if your garden has narrow passages between buildings or fencing.