Headband...

LED Flashlights – General Info 26650 Flashlights
1

:bigsmile: Head strap adjustable for 26650 and 18650
where to look?

2

You mean something like this:

http://www.intl-outdoor.com/nitecore-headband-hb02-2nd-generation-p-305.html

3

The NiteCore HB02A is a little cheaper here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270825520116