The safe, easy, and effective way to keep your baby sleeping longer and more peacefully. Thoughtful, easy-to-use design is ergonomic, "escape proof," and comfortable for baby. soft. ergonomic. easy. The Ergobaby Swaddler is made of soft and breathable 100% Cotton knit terry. This material stretches with any movement and is great for year round comfort. The Ergobaby Swaddler is easy to use and has an innovative ergonomic design that combines several unique features to ensure your baby sleeps longer, safer and more peacefully. Ergonomic Design – The patented Healthy Hip Positioner keeps baby's legs and hips in the proper ergonomic position.