every sequence of Roor bong comes in a dissimilar glass depth unreliable from 3.0mm, to 4.2mm, to 5.0mm and 7.0mm. All Roor bongs are heat-tempered absent of Schott Duran borosilicate glass tubing and are pass blown by german glass blowers. The Schott Duran tubing used gives Roor bongs the chemistry lab / examination tube appear that they are so well-known for. The majority Roor bongs are 3 piece design, consisting of the most important bong corpse, a downstem, and a bowl.