Patent ID: 7346955

Claim:
A device comprising: a first sheet and a second sheet, the first sheet being connected to the second sheet in a connecting region; a cavity formed between the two sheets on one side of the connecting region, wherein the cavity is accessible from an exterior of said device through at least one opening; at least one flexible strip, formed by at least one of the first and second sheets, on another side of the connecting region opposite to the one side on which the cavity is formed; wherein the two sheets respectively have a polygonal shape, and said cavity is oriented obliquely relative to said sheets, wherein said at least one flexible strip includes a plurality of flexible extensions, each of said plurality of extensions having a first end coupled to said connecting region and a second free end, said plurality of flexible extensions including at least one extension in which said second free end is spaced from a perimeter border of said one of said first and second polygonal sheets.