This exclusive 1" thick organic wool infant pelt is perfect for under baby, it's so soft and dense. You can put the baby on top without covering it. Use on any mattress to make it softer, on the floor for a play mat, or as a bedside rug when baby grows to a toddler. Wool helps regulate body temperature for comfort in all seasons; hospitals use wool pelts for premies to stimulate them. So unbelievably breathable you do not have to fret that your baby may have trouble breathing on these.