At first sight this little yellow box might seem a slightly incongruous inclusion in a gear guide full of jackets and tents. In the UK at least, Kärcher are probably best-known for making industrial-grade cleaning equipment – steam cleaners for carpets and the like. But with the OC3 portable cleaner they’ve developed something of a game-changer, and one that will make it far easier to look after your kit properly.

The Kärcher OC3 is in essence a very simple device. It’s a battery-powered washer that pumps out water with enough force to spray the mud off a jacket, backpack or tent. What makes this so brilliant is how portable it is. The OC3 is a 27.7 x 23.4 x 20.1cm cube, easy to lift even when it’s full of water and small enough that it hardly takes up any space in your car.

“…easy to lift even when it’s full of water and small enough that it hardly takes up any space in your car.”

The tank carries four litres of water and the battery (which charges from the included mains adapter) lasts for 15 minutes when fully charged. In testing we got around two minutes of spraying at full power before we ran out of water – more than enough to get the mud off several pairs of boots and the bottoms of our group’s hiking trousers before we jumped back in the car.

If you’ve got loads of really muddy gear, you may want to look at getting the Adventure Accessory Box (pictured here) which fits easily onto the bottom of the unit and retails for £38. It’s got a brush attachment (useful for getting mud out of the eyelets of boots and other fiddly places) and a separate hose which sucks water into the unit from a bucket or stream, giving you more cleaning time.

The spiral hose is 2.8 metres long at full stretch, which makes cleaning something the size of a two-person tent easy. And of course if you’ve got anything larger you can always pick the unit up as you walk around it.