Driving impression: Biso Ultralight 800 header It’s inevitable that the potential 12m/40ft working width of the Biso-Schrattenecker Ultralight 800 header will grab the headlines. Header width, after all, tends to be what limits the true potential of a high-output combine, given the right conditions. Look closer, though, and there’s a bevy of detail touches that make the Ultralight an interesting product – and for more than just its sheer size. James de Havilland reports