My five year old son was so overwhelmed when he first saw this he wouldn't even try it on.  After his excitement level calmed down, we adjusted it for his head size.  That was pretty easy on only took a few minutes.  With a little practice he was able to get it on and off himself (the nose has to fit on just so).  He's had a great time being "Spider Man."

There is a little button on the side that plays back a few canned Spider Man sentences.  That part is a little annoying, but my son seemed to get bored with that part pretty quickly.  The mask is really well made and I expect it will last a while.  I think this is going to be a great pretend-play toy for him over the long term.  He certainly seems to be enjoying it now.