The SOMATEX® soft drainage set ONE-STEP is a drainage device with multiple unique functions, offering a complication-free direct puncture where fluid collection is performed on the surface. The direct punctures are allowed by a sharp trocar, making the use of a guidewire or exchange dilatation no longer necessary. This allows for a more flexible puncture in the CT when under spatial limitations. It offers the following advantages over its competition: Drainage catheters are crafted from soft and unbendable polyurethane, the high barium sulphate provides very good x-ray contrast viewing, a very smooth catheter surface, supreme drainage through the oval-shaped eyes on the sides. The ONE-STEP comes equipped with the following: Pigtail drainage catheter with oval side eyes, an obturator for catheter stretching, a mandarin with a sharp puncture cutting edge, attachment tape, a 3-way valve, and a 1.5L secretion bag.