Tail swing is how far the rear of the upper structure extends beyond the undercarriage when the machine rotates. A conventional machine needs that space behind it; a reduced-tail-swing or zero-tail-swing machine stays closer to its own footprint.
On narrow streets, beside live traffic or against a wall, less tail swing means you can work without closing the lane. The trade-off is usually a tighter cab and sometimes less lifting capacity at the rear.
Ask us for the model, tonnage or destination you have in mind — we reply with matching units and an FOB or CIF quotation.