Straight suction tubes (PE or PA) have the advantage that they are not slightly bent as is the standard tubing (from the roll) and can therefore be immersed absolutely vertically into the container. The suction tubes are available in transparent PE for general sampling and black PA for flammable liquids in VbF Hazard Category AI (electrically conducting). Diameter 6 x 8 mm. Contamination banned! In practice the low-priced tubes are only used once. They are then disposed of, instead of being subjected to a costly cleaning process. The tubes are not autoclavable.