The earliest known example of a man using a condom during intercourse comes from a 12,000 to 15,000-year-old cave painting in the south of France. In the 16th century, Italian anatomist Gabriello Fallopius developed an eight-inch linen sheath for men to drape around their penis (the linen was tied in place with a pink bow). In his book, Fallopius stated that this invention helped 1,100 men prevent syphilis.

Though this method of contraception has been around for thousands of years, we still enjoy brushing up on our condom knowledge every now and then. After all, the male condom has come a long way from Fallopius’ original design. Countless options are now available in a wide variety of sizes and materials — even flavors and glow-in-the-dark colors.

In addition to reviewing the basics, like what condoms are and the benefits of using one, we’ve also put together some shopping tips and instructions on how to slide one on — banana totally optional.

The basics
Male condoms are small, thin stretchy pouches usually made out of latex, polyurethane, or lambskin that cover a penis during vaginal, anal, or oral sex. They prevent pregnancy and the spread of sexually-transmitted diseases (STDs) by acting as a barrier and keeping individuals from coming into contact with a partner’s bodily fluids, like sperm or genital discharge. Condoms can also limit skin-to-skin contact, which is helpful for preventing STDs like herpes. Even if you’re using another form of birth control, like the pill or an IUD, condoms are still the only type of contraception that protects you from STDs.

Condom considerations

When you’re perusing condoms online or at your local drugstore, supermarket, convenience store, doctor’s office, or community health center, keep in mind that while all condoms work to prevent pregnancy, only plastic and latex condoms prevent STDs. Condoms made from lambskin do not protect against STDs — only pregnancy.

“All latex and plastic condoms provide similar protection against pregnancy and STDs,” write experts at Planned Parenthood. “Whether they’re strawberry flavored, glow in the dark, or regular ol’ condoms, just check the box or wrapper to make sure it says that the condom protects against STDs and pregnancy.”

If you’re allergic to latex, plastic condoms are your next best bet for both pregnancy and STD protection. It’s also important to consider what type of lubricant you like to use, if any. If you decide to go the latex route, lubricants with oil and petroleum in them (coconut oil and Vaseline for example) can damage latex condoms. Instead, reach for a water or silicone-based lubricant or choose a condom made from another material.

Finding the right fit
Before you toss a chocolate chip cookie dough-flavored latex condom into your cart, don’t forget about size. After all, condoms that are too tight could break, while those that are too big could slip off or encourage leakage.

Similar to the hunt for the perfect pair of jeans, it can take some experimentation to find a condom size that’s not too small, not too big, but just right. Buy a wide variety and try them on before turning things up in bed. “Start with a regular condom,” advises Planned Parenthood. “Does it roll on easily and stay in place? [If so] It’s the right size.” Does it feel loose or look like it’ll slip off? Go for a smaller size, which are sometimes labeled as “snug.” On the other hand, if the condom is painfully tight or looks like it’s about to rip, go up to a “large” or “magnum” size. Still too tight? Try one labeled “extra large” or “XL.”

Wrapping it up… literally
Now that you’ve found the right size, need a refresher on how to use condoms? Check out this detailed and visual guide from the Centers for Disease Control and Prevention (CDC). We like that, in addition to walking you through how to put a condom on pre-sex and remove it post-sex, it includes helpful tips like always looking for the condom expiration date. (You may need to toss the ones you still have from college.)

And it’s always a good idea to always use a second form of birth control (like the pill, IUD, ring, implant, or shot) to prevent pregnancy in case the condom breaks or a mistake is made. “If you use condoms perfectly every single time you have sex, they’re 98 percent effective at preventing pregnancy,” says Planned Parenthood. “But people aren’t perfect, so in real life condoms are about 85 percent effective — that means about 15 out of 100 people who use condoms as their only birth control method will get pregnant each year.”

That’s just another reason to check out the above guide to perfect your skills. Next time you need to re-stock, pick up a pack of condoms for your purse, bathroom cabinet, or bedside table, you’ll be well-educated on one of the most confusing products out there. Magnum? Lambskin? No sweat! When you eventually head to the bedroom to actually get a little sweaty, you’ll have even more fun knowing that you’re also playing it safe and smart.

English Taylor is a San Francisco-based women’s health and wellness writer and birth doula. Her work has been featured in The Atlantic, Healthline, Refinery29, NYLON, and Modern Fertility. Follow English and her work at https://medium.com/@englishtaylor or on Instagram at @englishtaylor.