Double row of barbs - Unidirectional or bidirectional. Barbs that encircle the thread 360ยช, Thicker and stronger reinforced barbs - Different thread gauges, from 1 to 3-0 - With or without a pulling or traction system - With or without a distal opening 23G, 20G and 19G needles. - Blunt tip 20g and 19g needles