KIMAX® Kjeldahl connecting bulb has a curved inner tube sealed to the upper arm to prevent carry-over during distillation. Lower tubes are 11 - 12mm O.D. to fit special Kjeldahl stoppers. Both the upper and lower tips inside the bulbs are arranged so that counterflow of liquid and vapor is not impeded when the bulb is inclined to the rear. Outer Diameter: 55mm. Length: 100mm. Kimble® #: 16040-55.