my daughter start in a swaddle and upgrade to the sleepsack . Halo make a top notch product and this be we second size increase in this product . we also have the cotton for summer and the fleece for winter . she be squirmy and would never keep blanket on so this be the perfect solution . also no need to worry about cover tangling or go over she head . a sound warm sleep for she and a little piece of mind for I !