It’s every parent’s worst nightmare: sudden infant death syndrome, or SIDS. But there’s a very easy way to prevent it, experts say, and the item is starting to grow in popularity in the United States after enjoying plenty of success in Finland.

It’s called the baby box, and in New Jersey alone, thousands of parents are putting their infants to sleep in what is nothing more than a cardboard box as part of a public health initiatve to cut down on SIDS, which claimed the lives of 3,700 babies nationwide in 2015 alone.

“It is not safer than a crib, that is meeting all the recommendations for safe sleep,” said Dr. Kathryn McCans is a pediatrician at Cooper University Health Care in Camden, New Jersey, and the chair of the New Jersey Child Fatality and Near Fatality Review Board, in an interview on NPR’s Here & Now show. “This program is really meant to decrease what we call SUID deaths, which is sudden unexpected infant deaths. Those deaths are comprised of SIDS, plus a number of causes of sleep-related death that are impacted by the environment the baby’s in. So these deaths can include accidental overlying when the baby’s sharing a surface with another person, suffocation when they get trapped under blankets or in pillows, strangulation if something wraps around the baby’s neck, entrapment when the baby gets stuck between a poorly fitted mattress, or cushion in some other surface that’s part of their sleep environment.”

The details of the New Jersey Baby Box Initiative from the Southern New Jersey Perinatal Cooperative are as follows: “Designed to serve as an infant’s sleeping space for the first months of life, Baby Boxes are made out of durable cardboard. Inside each box is a firm mattress and a collection of products including diapers, accessories to assist with breastfeeding, baby clothes and other items. In addition to receiving Baby Box, recipients will also get access to a digital library of health education material through Baby Box University. The use of Baby Boxes originated in Finland, where they are credited with helping that country achieve one of the lowest infant mortality rates in the world. The success of the Finnish Baby Box intervention inspired the founders of The Baby Box Co. to adapt this tradition with enhanced multi-media parenting curricula through Baby Box University to the benefit of nonprofits, hospitals, government institutions and individual families worldwide.”