This straight tube bong from Grav Labs is one smooth puppy. The fixed down stem feeds into the base beneath a honeycomb percolator which breaks up your smoke into super tiny bubbles with massive surface area which allows them to cool down as quickly as possible. Then above that there is one of Grav's signature ice pinches which allows you to drop in a couple of ice cubes and drop the temp of your hit another few degrees. The removable down stem has a multi slot diffuser at it's base and uses a 14.5mm female ground joint which matches up nicely to the 14.5mm ground glass joint.