Wolf-Pak® 6" SmartSite® Exrension Set, 0.9ml priming volume. One of the most widely used in the world earning its reputation as a proven, reliable system. Flat, smooth top: easy-to-swab. Straight-through, non-tortuous fluid path: reduces the risk of hemolysis. Passive system: increases compliance and eliminates the need for caps and cannulas. High chemical compatibility and lipid resistant: suitable for use with a wide variety of drugs.