PW-66 4 Bar Chevron Boards, also known as PW66, WYS4 or a W20-1 sign, are used to advise the direction & speed around a corner and provide delineation on horizontal curves. Can be used in conjunction with the PW-67 1 Bar Curve Indicators. Consists of a 4 bar chevron design wtih a speed indicator, displayed on a standard permanent warning PW chevron sign. Please specify required speed and direction (left or right) at time of order.