Purple colored Luer Lock hub with a 21 gauge blunt tip. The Inside Diameter is 0.020” (0.510 mm) and the Outside Diameter is 0.032” (0.820 mm). Our NT Series Premium polished tips feature a polypropylene plastic double-helix hub with a UV-bonded stainless steel cannula. The burr-free tip design allows for precise dispensing with no residuals. Available in boxes of 50 or bags of 1000.