Choose the chipper based on the maximum branch diameter you regularly process. The 100mm model handles material up to 4 inches in diameter — the majority of domestic and light contractor work. The 120mm model handles material up to 4.72 inches — for professional tree surgeons and grounds maintenance contractors processing significant volumes. Both models use JCB petrol engines and belt drive for reliable operation. Feed branches butt-end first at a consistent pace for best chip quality. Wet and green material chips slower than dry — work in shorter bursts and allow the machine to clear. The 360-degree rotating chute directs chip where you need it without repositioning the machine. The off-road ATV towing bar (not road-legal) allows both models to be towed to remote locations behind suitable plant or tractors.