Above: D04 : The thickness of the ribs is also reduced to 30mm and 20mm thus giving the helmet a sleeker design. This is brought about by the use of Double wall (Bc) cardboard with a thickness of 6mm. By increasing the ply of the board more strength can be achieved in a smaller width.
The inner surfaces of the ribs, which are in contact with the head, have airshafts running through the entire length of the helmet.
Above: D04: The D04 also steps away from the flat base plate to hold the ends of the ribs. Instead the penultimate ribs act at the end plates for the helmet. Thus giving a unique profile to the helmets. The inclined penultimate plates also make the helmet look visually thinner. The stress during impact is better distributed over the entire plate rather than a concentrated point.
