All shipments along the route from Glasgow to Dover ... that means ... Glasgow-Manchester-Birmingham-London-Dover are charged at £ 1 / kg.
The minimum weight is not limited, but for the first 20 kg, the unit price is £ 20.
The minimum price for Zone 1 is £ 20 / for all shipments up to 20 kg, Zone 2 - £ 24,
Zone 3 - £ 30