The Magic Sleepsuit is a great swaddle transition product. It is best introduced when babies are outgrowing/breaking out of the swaddle. The Magic Sleepsuit offers the next step from the swaddle as it provides babies with a cozy, secure sleep environment to help muffle their reflexive startles and aid in their sleep but yet does allow movement. The Magic Sleepsuit is designed for back sleeping in a bare crib. The crib should be approved by the Consumer Product Safety Commission (CPSC) and have a firm, tight fitting mattress with a tight fitting bottom sheet. There should be no soft objects or loose bedding in the crib. We suggest that you begin using the Magic Sleepsuit with naps and check on your baby frequently the first few days to monitor your baby while in the Sleepsuit. Proper fit and timing of introduction are very important to the effectiveness of the Magic Sleepsuit. If it is introduced too early or too late, it may not be the right match for your baby. It is designed for a specific developmental window. Please feel free to call us and we will be happy to answer any questions you have about timing of introduction.