That sounds like a great addition to the Holmer Terra Dos 5-40 harvester! The Holmer HR6 headers for Potato, Beetroot, Carrot, and Parsnip seem to be well-designed with a decent working width of 2.7 meters, allowing for efficient harvesting. A working speed of 20 km/h is quite impressive and can help in quick harvesting operations. With a powerful engine of 652 hp, you can expect smooth performance even in challenging conditions. The impressive capacity of 250,000 liters ensures that you can harvest a large quantity of crops before needing to unload. Overall, these headers seem to be a valuable extension to the Holmer Terra Dos 5-40, providing efficiency and productivity during harvesting tasks.