The Bushranger BP451 Backpack Brushcutter is a commercial quality unit with a 41.5cc engine: mounted on a fully adjustable backpack for maximum operator comfort. A Chrome impregnated cylinder: giving a longer life than a standard engine. Reverse Start: only requires one-third the effort to start. Four bearing gear case: runs smoother and longer under commercial applications and an Anti-vibration system: significantly reduces operator fatigue.