An insulin pump is a small device about the same size as a pack of cards, which looks similar to a pager. Inside is a reservoir containing your insulin, which is attached to you via a long piece of thin tubing. At the end of this tubing is a needle or cannula inserted under the skin, enabling the insulin to flow into your body. The pump is not automatic, but is programmed to deliver insulin constantly, at varying rates which you determine. This means that you no longer have to give yourself injections.