Insulin moves from your insulin pump’s reservoir to your body by way of an infusion set, a combination of tubing and a cannula or needle that’s held to the skin with adhesive. Aside from the OmniPod (which is tubing-free), all insulin pumps work like this: The beeper-sized device releases insulin from its reservoir. The insulin winds through flexible tubing that’s connected to the pump and enters the body through an under-the-skin cannula or needle. Every two or three days, you’ll remove the old infusion set and replace it with a new one, rotating the site on your body to prevent infection or irritation.

While each infusion set has the same general setup, there are some key questions you should ask yourself:

What’s better: a cannula or needle?
The decision is a matter of personal choice, though few people still use a needle that’s left under the skin. Instead, most opt for a plastic cannula. A needle guides the cannula under the skin but is removed once the cannula is in place.

Should I use an insertion device?
Some infusion sets are inserted under the skin manually. You slide the needle or cannula under the skin and secure it with adhesive. Others use handheld devices that insert a needle or cannula with the press of a button. Insertion devices make injection easier, and they’re ideal for people who have a fear of needles.

What type of needle is best?
You and your doctor or diabetes educator will discuss needle options (length, angle, and gauge) and pick the best fit based on your size and activity level. A thin person or child, for instance, may need a short, angled needle to avoid inserting into muscle. Someone with more fatty tissue might do well with a larger, longer version.

How do I choose among tubing lengths?
Most infusion sets offer a range of tubing lengths, and the one you choose will be based on your height and the distance between your infusion site and your pump.

What is the difference between tubing that disconnects “at site” and tubing that disconnects “away from site”?
Whether you go for a swim, take a shower, or roughhouse in the backyard, there will come a time when you’ll need to take your pump off. But that doesn’t mean you need to remove your entire infusion set. Some tubing detaches right at the site, leaving only the cannula and adhesive in place. Other tubing disconnects a few inches away from the site, leaving behind a trail of tubing, the under-the-skin cannula, and adhesive. The away-from-site option is ideal for people with shaky hands, dexterity problems, or vision impairment because there’s less risk of tugging the adhesive and accidentally removing the cannula.

What does “Luer lock” mean? And why is it important?
The term describes the connection between insulin pump and infusion set. Most pumps use this type of lock to secure the tubing and seal insulin inside the pump. Pumps that have Luer-lock connectors work with most infusion sets. Though most people use sets designed by their pump manufacturer, other brands may be cheaper. Plus, if you experience skin irritation from one brand’s adhesive, you may want to try another. Two pumps (Medtronic’s MiniMed Paradigm Real-Time Revel and Sooil’s Dana Diabecare IIS) only work with their own sets.