These Pyrex® filling bells are ideal for aseptically filling culture tubes and bottles. Rubber tubing is attached to the top of the tubulation while the receiving vessel is placed inside the bell. The smaller size will fit tubes up to 20mm O.D. (without lip). The larger size can be used on bottles with maximum rim diameter of 44mm. Pyrex® aspirator bottles (Cat.Nos. 1-1220 and 1-61220) have a bottom sidearm tubulation that can be used with these filling bells to aseptically dispense sterile media and solutions.