Long time ago, the bjorn and kelty back pack were in wide use for my baby at his age of 6month old, which leads to a big pain on mu shouders during the whole running all day long. But nowdays, a client advised me to choose this Ergo backpack, so I purchased this carrier. As time pass by, I feel happy about it. This type of carrier features lightweight and great ease for my shouders and neck. My baby likes it very much. It allows me to put my baby into or off more easily with the help of this carrier. The one moment you try it, it seems fantastic! I introuduced every mother to use this model that serves for they babies' use. I am ready to place a order for baby shower too. This goods seems very wonderful. I am crazy about ERGObaby!