All too often, our penises don’t work the way we want them to. We can’t get or maintain an erection, even though we’re really aroused. Then, of course, many cisgender guys wish they had a longer and thicker penis.

If you’ve ever struggled with erectile dysfunction (ED) or you’re packing on the much smaller side, you may have heard of a penis sleeve, or perhaps one of the many other names for the revolutionary device: cock sleeve, penis extender, external penile prosthetic, or penis sheath. It’s likely left you thinking: what exactly is this bizarre contraption, how does it work, and do I need (or want) one?

Well, to start, “Penis sheaths are devices that go over the penis, in order to modify its ability,” says Michael Ingber, M.D., a urologist and urogynecologist at Garden State Urology. “There are varying types. Those which add length in men who feel a bit too short, those which add girth in those who want a thicker penis for their partner, and those which add texture (e.g. ribbed outer sheath).”

To answer the rest of the questions we not only spoke to Ingber, but also to Jessie Cheung, M.D., a board-certified dermatologist who has vast experience treating men with various penis issues. Together, they helped to provide nearly everything there is to know about penis sheaths.

How does a penis sleeve or cock extender work?

Most penis sleeves slide onto the penis like a condom, and function to enhance pleasure or improve functionality. “Penis sleeves were originally developed for medical purposes,” Cheung says. “Primarily, they were created to allow for penetration by men with erectile dysfunction, or to trap blood in the penis to maintain erections, or to reduce sensation for men with premature ejaculation.”

More recently, however, penis sleeves or extenders have become popular as sex toys. “They increase girth and length and can have nubs or ribs on the external or internal wall to provide stimulation for either partner,” Cheung says. So if your penis is significantly below average—remember the average erect penis is only 5.16 inches—a penis sleeve could be a helpful tool to add a few inches to your penis.

Are there various types of penis sleeves and cock extenders?

Yes, which partly explains why there are so many names for the device. There are penis sleeves for men who can’t get hard at all, and there are sleeves that work as long as you start erect and are then able to put on the device. These devices will help to keep you erect.

Men's Health Magazine

Men's Health Magazine

Then there are completely sheathed sleeves where your entire penis is covered. Other partially sheathed sleeves have an opening for the head of your penis, whereas other sleeves focus on adding girth to the base of your penis (for men who are blessed with length but want to add circumference). Then there are penis head sleeves if you wish to increase the size of your head. (So yes, there are options for every single shaped penis in existence!)

Last but not least, you have devices like the Elator and Erektor, which aren’t so much sleeves as they are extenders. Unlike sleeves, they don’t add artificial girth or length. These external penile devices have two fitted rings, one that goes around your penis base and the other around your head. There’s a rod that connects the two rings, keeping your penis erect and stretched out. It’s a potential option for men with mild to moderate ED.

A 2017 study published in Translational Andrology and Urology reported that some men who struggle with severe ED were actually able to reach orgasm while using a penis sleeve.

What are penis sleeves and cock extenders made from?

Penis sleeves are typically made out of silicone, though some are made out of rubber, latex, or plastic. “Make sure you don't have any sensitivities to the material being used,” Ingber says. “Several penis sleeves may contain latex, and many people have an allergy to this. Others are made from silicone, which is generally well-tolerated.” It’s also worth noting you can also buy a sleeve that vibrates, which can feel pleasurable for both you and your partner.

Are penis sleeves and cock extenders safe?

Yes. “A penis sleeve is a safe and effective alternative to surgery or medication for men with ED and is an easy tool to add variety to your sex life,” Cheung says. That said, penis sleeves and cock extenders are stop-gap measures. They don’t get to the root of whatever is causing your erectile dysfunction. They just help you in the moment if ED is something you struggle with. That’s enough for some men, but it may be helpful to speak to your doctor about other methods that help with ED long-term.

But do make sure to wash them regularly to avoid any infections, Ingber adds. “And like regular sex, be careful; having a penis sleeve does not protect you against things like STIs or injuries like penile fracture,” he says. So take it slow, use lots of lube, and enjoy yourself.

Are there other non-surgical options to enhance penis size?

Yes, and we’ve written about them extensively, but Cheung provided three options she recommends for long-term size increase: penis filler injections, P-Shot injections, and penile laser treatments.

“Dermal fillers are not FDA-approved for use in the penis, but they can be safely injected by an experienced physician to increase girth, and can also increase sensitivity,” Cheung says. The P-Shot is a trademarked procedure that includes platelet-rich plasma injections to the penis and mechanical pumping to improve size and function. Stem cells and exosomes can be added to the classic P-Shot for greater tissue rejuvenation, Cheung adds. Last but not least, Cheung notes lasers are used to increase circulation and boost collagen, “giving lasting improvements in size and erectile function.”