The cobra s390b is a push petrol scarifier suited to medium to large size lawn areas. With a petrol model you have the freedom to work anywhere without the drawback of electrical cables or leads. Lawn scarifiers help to clear moss and thatch which can take hold and allow the grass and ground to become matted. With a scarifier the hard surface is penetrated with the blades which allows the grass roots to breathe and take in essential extra nutrients including oxygen and moisture. When the lawn is dry mow the area first, to a height of about an inch then use the scarifier. It is recommended that after scarifying you immediately use a fertiliser for a nice green lawn. The cobra s390b has a 38cm 15 working width and the machine is fitted with a quality briggs and stratton 450 series engine. Complete with a 45 litre fabric debris collector. The working height can be adjusted with a central lever from 0 10mm.specificationsengine briggs stratton 450 seriesdrive hand propelledfuel unleaded petrolworking width 38cmblades 16 metalheight adjuster centraldebris collector 45 litreswheel size front rear 20cm 8 weight 30kgwarranty 2 years domestic