Glass liquid addition system is fabricated from type 1 class a borosilicate glass with vertical and horizontal hose barbs (9mm od x 3mm id), vertical for liquid addition and the horizontal for pressure venting of the reactor vessel during operation. The bioreactor model includes a fitting and o-ring for attachment to any stainless steel bioreactor head plate with an 18mm port. Overall dimensions of glass addition tube (lxw): 4 1/2"x1 3/4" .