PDO Threads BC Type (21G-60mm-115mm)BC type *PDO Threads are made after ordering, the delivery may be delayed by 2~3 business days" Compared to normal needles, BC type provides smoother insertion of needles into skin layers and minimizes skin damage. Model Number Needle Gauge Needle Length Thread Length USP Size One Package CNS 21 01 21G 60mm 115mm 2 0 20pcs Minerva Cannula is different from any other company's products since the company has its own manufacturing method. MINERVA Cannula