This PYREX® centered gas dispersion tube with fritted cylinder has a coarse porosity (40 to 60µm) fritted cylinder and is used to disperse or scrub gas in liquids. The size of gas bubbles depends upon the porosity of the fritted cylinder and the liquid used. The finer porosity discs give smaller bubbles, however greater gas pressure is required. Centrally located stem permits insertion through small openings. Dimensions: (H x Stem O.D.) 250 x 6mm. Disc Diameter: 30mm. Porosity: Coarse. Material: Borosilicate Glass Code 7740. Corning® #: 39534-30C.