Inline and Dual Arm Percolated Glass Water Pipe 18"Inline and Dual Arm Percolated Glass Water Pipe 18" \n \nCheck out this awesome heavy duty scientific glass bong that features four different smoke enhancing features. First your smoke enters the fixed downstem and is filtered through a multi slit inline percolator. Then it travels up the water pipe's body before it is filtered through two tree percolators. These dual percs create some great filtration and really cool bubbling. The last feature is a 3