Double honeycomb perc for water pipes. These honeycomb perc have both joints of 14mm and it takes 14mm glass bowls. Water pipes that are like a straight tube are the best water pipes for one of these honeycomb percolator as they have both joints of 90deg. These honeycomb percolator have two honey comb discs. Based on reviews it can easily be said that honeycomb perc produces the smoothest smoke out of your water pipes.