Syringes deliver a reliable system of fluid and gas transport in both laboratory and general conditions, as well as an efficient fluid-delivery mechanism. They can also be used in non-research or medical applications such as injecting glue into tight repair joints in workshops or for refilling ink cartridges in fountain pens. Constructed of polyethylene or glass bodies and stainless steel tips, syringes are convenient and generally inexpensive, making them a universal tool across professions.VWR offers various types of syringes including Luer lock syringes which offer a secure connection, Luer slip syringes which offer a quick way to attach a needle, catheter tip syringes which are used when a regular slip tip needle is larger than a normal slip tip needle and insulin syringes that come with an attached needle. The barrel of insulin syringes are typically marked with the units of insulin.