I bought this mask to complete my grandson's spooky skeleton costume. for Halloween! It fit his head perfectly and the 2 part battery pack went together perfectly and the cord is long enough to fit into his pocket. Runs on 2 AA batteries that goes into the battery pack ( not included). I love that the batteries and pack fit into his pocket and aren't near his head. With all the talk of batteries and what they can do to kids' heads this design was very well thought out. This was $12.99 well spent! I highly recommend this mask to complete your little one's Halloween costume!