Medical studies have shown that babies sleeping in Merino wool settle more quickly, wake and cry less, sleep longer and gain weight faster. Significantly finer than other types of wool, our Merino is the perfect fiber to have next to child's sensitive skin. It breathes, regulates temperature, manages moisture, it's silky-soft, easy to care for, and durable. It is naturally perfect. Merino absorbs and then removes moisture away from baby's body creating always a perfect sleep environment for your child. Unlike any other fiber, Merino is warming even when wet, a very important benefit when nighttime accidents occur. Merino regulates body temperature so baby won't overheat or wake up cold. Merino wool is naturally fire resistant and Woolino products have not been treated with dangerous fire-retardant chemicals often found in other polyester or cotton baby/toddler sleepwear. Machine washable and quick drying. Comfortably lightweight and silky soft, Woolino pajamas are perfect for layering inside a Woolino Sleep Bag or wearing underneath other clothes. This is a pajama set including pajama top and pajama pants.