Straight Cannula 25G x 40mm + 23G Pre-hole Needle A comprehensive range of twin-packed Silkann flexible aesthetic cannulas and Sterimedix sharp needles – designed for operational efficiency and with your patient’s comfort in mind Each cannula with screw thread polycarbonate hub, is supplied one size smaller than the accompanying sharp pre-hole needle, giving practitioners the perfect match between cannula and needle to ensure maximum accuracy whilst maintaining optimum patient comfort.