Abstract: A filter has a shell construction including a connection surface and a bar-like resonator in the shell construction. The bar-like resonator has an initial section having one end region thereof connected to the connection surface of the shell construction and an opposite end region. A substantially straight and elogate intermediate section extends from the opposite end region of the initial section to an end and a turning-point section extends from the end of the intermediate section to an end. A substantially straight and elongate end section has one end connected to the end of the turning-point section so as to extend adjacent to the intermediate section and supporting means connect to the connection surface of the shell construction for supporting the bar-like reasonator at least at one of the end section and turning-point.

Abstract: A method is disclosed of shaping and a series of shaping implements for slalom boots, in which the slalom boot consists of a hard plastic outer shell and an inner boot manufactured from a flexible material. In accordance with the invention the boot is shaped to a perfect fit for the user as follows: a boot of the correct length is selected in accordance with the user's foot; the individual forms of the foot protruding from the boot are recorded; a point in the outer shell corresponding to each protrusion is shaped as follows: the point to be shaped is heated locally from the outside by hot-air blowing; the heated point is pressed from inside by means of a wooden piece, when the plastic material stretches and a protrusion arises.