The 500ml high-capacity sampling tube is compatible with most dissolution baths. The VanKel tube filter membrane is fixed in a twist lock, which means that the same filter membrane can be used in different dissolution baths, providing you with more flexibility. The surface area of this type of filter membrane is seven times that of traditional sheet-like filters. The high-capacity sampling tube can be kept in the dissolution cup throughout the experiment without affecting the experimental results. Removing it requires an automatic needle extractor. The catheter is fixed on the dissolution cup lid and samples are taken at the same position every time.