The present invention relates to a polymer film comprising a polymer having liquid crystallinity, having a number-average molecular weight in terms of polystyrene of 103 to 108 and having an electron mobility or hole mobility of 10\u22125 cm2Vs or more, and having a film thickness in the range from 1 nm to 100 \u03bcm. The filter device assembly generally includes a structure having a collapsed state and an expanded state with first, second, and optionally N additional filter members circumferentially attached thereto. Thus, the effective length of the snowboard binding can be adapted to the respective boot.