The otherwise open end of the outboardmost belt guard over the interface between the flexible cutterbar assembly and flexible draper assembly of a harvesting header is closed by a deflector to prevent the ingress of crop residue into the void region defined beneath the overhanging belt guards. A first contact layer is provided so on application of an electric field charge carriers having a polarity are injected into the semiconductor particulate through the carrier material. The lower end of the suspension element is connected to a second support member rotatably connected to the disk on the wheel. The posterior frame portion is attached to the arcuate base and is configured to curve upwardly between the buttocks of the wearer. Two axially spaced circumferentially continuous parallel ribs 14 straddle the tire centreline and project radially beyond the block tread pattern to improve ride quality on a smooth road surface.