Scarifiers, also known as rakers, are intended to aerate lawns. Aeration clears the turf cutting out moss, leaves and the sward that can occur through winter months affecting grass breathing or nutrients to penetrate the soil. Lawn scarifier has three working systems: with blades, with free-swinging blades and with springs. The blades rotate quickly penetrating and scarifying the soil; they literally scratch the soil removing compact residues that can occur through winter. Free-swinging blades work with fixed blades and make holes to get fertilizers and organic substances into the soil in order to feed the lawn. The blades are the most efficient working system because they not only remove any debris on the lawn but also make some holes for feeding fertilizer. Lawn scarifiers with springs are easier to use and are intended for thick grass on which is only necessary racking the lawn. Spring blades just rake the turf and don’t make holes in the soil. Therefore, they just remove the residues without penetrating the soil. As petrol scarifiers/lawn rakers are powerful machines intended to work on big surfaces and for hard works, they are well suited to professional uses. They are mostly powered by Honda or Briggs&Stratton engines and are equipped with a rear collection bag. Electric scarifiers/lawn rakers are intended for small surfaces and for domestic uses, such as on yards. They are equipped with a rotor with blades or with springs as well, which can be interchanged according to the model, and are intended to work on small yards. Moreover, they must be connected to a power outlet. In all the models the height is adjustable according to the hardness of the soil.