At the time of purchase my son was 7 months old... we were going to Iceland for 2 weeks. This pack was perfect! My little one fit perfectly and was quite comfortable-- he enjoyed it even with the long hours of hiking and exploring. The little cover that comes with this pack came in handy as well. He stayed dry! He absolutely loved it (still does at 9 months). This is a great pack not only for the little one riding but great storage space for everyone's needs! Diapers and wipes, extra clothing (for both baby and parents) and food. Most importantly, my husband, brother and I all took turns carrying the pack. We couldn't get over how comfortable it was to wear. The weight distribution of baby and pack was perfect. Great support to shoulders and lower back. I would recommend this pack to anyone in the market!