Bought this along with the Ernie costume for my husband and I for halloween, to celebrate with our 2 year old daughter.  They only had XL size left, which I purchased, and it seemed to fit fine (my husband is 6'1 and I am 5'3.)  Although the heads were quite big, and kept falling forward, doesn't stay in one place.  Have to kind of re-position the head while wearing it, which was a bit annoying, but maybe that's b/c I bought the XL size.  But in the end we received many smiles and laughs wearing them, which is all we wanted.