A method for providing information for the driver of a vehicle for parallel parking of the vehicle includes sending the driver information about the length of the parking spot in relation to the length of the vehicle. In particular, the present invention relates to techniques which seek to improve the throughput of data in multi-hop communication systems. The plurality of posts project from, and are arranged at a predetermined circumferential spacing along, the outer circumferential surface of the cylindrical portion; and each of the plurality of blades is provided on a respective one of the posts.