Climbing helmet in X-large?

Hello!

Please forgive if this is not the right forum for this question.

My stepson wants to take me on a climbing trip.

I have about all the gear I need for the trip but I can't find a helmet my size. I am 6-9 and my hat size is 8+.

Web site http://REI.COM got nothing for my size.

Can someone please point me to a web site that might help?

Thanks!

Al.