The Dori 520PRO is a petrol driven lawn scarifier with a 5.5HP Briggs & Stratton engine. The 520PRO has swinging steel knives which give a 21 inch scarifying width. The 520PRO features 210mm alloy wheels, folding handle & centralised height adjustment. Specifications Engine: 5.5HP 4 stroke Briggs & Stratton engine Belt drive with jockey pulley clutch Steel constuction 21 swinging steel knives 21" scarifying width 210mm alloy wheels with bearings Centralised height adjustment Manufacturer's 12 month warranty