i just have to write this for anyone whose baby LOVES to sleep with their arms up or doesn't like being swaddled, get this sleep sack!! my baby is almost two months old and sleeping so much! he slept well before hand but still woke up a lot, and woke himself up a lot. but since starting using this sleep sack he'd sleep a solid 5 hours then went up to 6. then the past week he's been sleeping an 8 hour stretch! followed 3-4 hours stretch. it also calms him down if he's fussy or a lil overtired. its made a HUGE impact because he's so much more playful and curious and joyful especially in the morning. also helped me sleep a lot which is great because i'm starting to feel like a real person again who's actually rested 😅 i'm a first time mom and this was recommended to me and i'm so thankful, so i just wanted to spread some knowledge if it helps anyone!