Love to Dream Swaddle UP Hip Harness Transition Bag is a swaddle that is specially designed for babies being treated for Hip Dysplasia. It has been designed with a wider fit at the bottom so that it can be worn over a Hip Dysplasia Harness or brace. It is the only zip-up swaddle with patented 'wings' for babies treated for Hip Dysplasia, that allows your baby to sleep in a natural position with ARMS UP. This transition bag enables you to zip off one wing at a time, allowing your baby to slowly adjust to 'arms-free' sleep. As soon as your baby starts showing signs of trying to roll, you must transition to 'arms-free' sleep.