US Patent 7987856 Smoking article with bypass channel

A smoking article having a tobacco rod of a smokable material and a filter system attached to the tobacco rod of smokable material. The filter system includes a first filter portion and a second filter portion, the second filter portion concentrically positioned with respect to the first filter portion and having a lower resistance to draw than the first filter portion during an initial puff on the smoking article. The second filter portion closes upon contact with the mainstream smoke of the initial puff, such that after the initial puff, the first filter portion has the lower resistance to draw.