Most cardiopulmonary resuscitation (CPR) mannequins, on which people learn how to do CPR, are missing one feature important to a significant portion of the population: breasts.

A new product is changing that, with the hope of saving the lives of countless women.

The Womanikin is an attachment with breasts that can go on any CPR mannequin, or dummy, to help people learn how to do CPR on something besides a flat-chested, male torso.

The product was created by a female-led ad agency, JOAN Creative, in response to a study that found women suffering cardiac arrest in public are 27% less likely than men to receive CPR from bystanders.

Assuming the statistic came because people are not trained on women's bodies and may be hesitant about touching women's breasts during CPR, JOAN Creative reached out to the study's author, Dr. Audrey L. Blewer, an epidemiologist and resuscitation scientist at Duke University, and created Womanikin.

"We know that prompt delivery of CPR can double the chances of survival from cardiac arrest," Blewer told " Good Morning America." "The bottom line is that we need to get more people doing CPR."

"Saving a life is simple," she said. "All someone needs to do is call 911 and push hard and fast in the center of a person’s chest."

The Womanikin attachment that can help people practice that life-saving move on women is free and can be downloaded via a tool kit available online.

In CPR instructions on the Womanikin website, its creators write, "Yes, this will mean you are touching her left breast. Don't worry. You might save her life."

Knowing how to perform CPR on a woman in cardiac arrest is critically important because heart disease is the leading cause of death for women in the U.S.

Among men and women, more than 320,000 out-of-hospital cardiac arrests -- when the brain cannot pump blood to the brains, lungs and other organs -- occur each year in the U.S., according to the American Heart Association (AHA).

JOAN Creative, which launched Womanikin during National CPR Awareness Week, has set a goal of having a Womanikin attachment in every CPR training school in the U.S. by the end of 2020.

"I am passionate about finding more ways to get people thinking about CPR, trained in CPR and surviving," said Blewer. "The more we can do to get more people trained in CPR for everyone, the better the outcomes will be."