Need Reflector I can pack

I'm sure there is a more technical term, forgive me for not having the right term..

Id like to put into my pack a 'small light reflector', you know the kind you open up, then use to get more natural light into shadows on faces for portraits, then pack it back up again. This isn't for a studio, need to pack it.

Need a recommendation, something inexpensive, functional and mobile.

Thanks in advance.

A collapsible reflector is a collapsible reflector. How do you plan to carry it? Do you have a specific space/pocket you plan to carry it in or are you just going to hang it off a pack like some people do?

I was hoping to put it in my camera back pack... but I'm open to suggestions on best practices. Its nice to have it when you need it.

The reflectors will come in a zipper pouch to hold it when collapsed and some people will just lash that pouch to the outside of their pack. I don't like to carry that way because I hate to have anything flopping around loose but it does allow you to carry pretty much any size reflector you want. If you are planning to carry it inside a pack then you need to figure out how much space is available for it. If you've got a space in the pack that is 12" wide then a reflector that collapses to 16" wide isn't going to fit.