A Venflon  is a small flexible plastic tube that is inserted into one of your veins through the skin.vaflon also known as intravenous cannula or iv cannula or cannula butterfly that is used for giving fluids, medication, collect blood sample in patients. Vaflon comes in different size such as 18g, 20g,22g,24g etc. available on Hospitals Store. You can buy  venflon 18g. vaflon 20, veflon 22g and other sizes of vaflon  online from "Hospitals Store".