Beaker Base Double Percolator Glass Waterpipe 45cm14mm Male connector Size This Waterpipe features a 14mm male connector size. It is compatible with all 14mm female connector bowl. Beaker Base Shape The beaker base shape gives the Waterpipe a scientific look and great stability. The shape is also very easy to clean. Donut Percolator The donut percolator has a round shape with a hole in the middle (like a donut). This design makes the water and smoke circling around it, creating diffusion and acting