America's favorite premium pipe filters. Dr. Grabow pipe filters are America's favorite pipe filter with more than 1.8 million packets being sold each year. They have been made for more than 60 years in Sparta, North Carolina. To ensure a consistent quality, Dr. Grabow filters are manufactured from five layers of specialty paper, spirally wound and sealed with a special top layer. They are then cut to a consistent length and packaged. Pipe smokers who use Dr. Grabow filters appreciate that the filter removes moisture gurgle from the pipe bowl and will help extend pipe life while still providing a pleasant, natural smoking experience. Dr. Grabow filters will fit most pipes available in the U.S.A.