Mini Maglite

Where can I get a red lens for my mini flashlight?
I'm trying to get a few things together for a configuration of astronomy basic, and I need a red light does not ruin my night vision. I found a lot of red lenses for Maglite Mini on the Internet, and are really cheap (0.75 U.S. dollars), but I do not want to pay you $ 5 in sending a 1-inch circle of plastic. Is there a larger hardware or electronics chain to sell?
I would try a local store of theater - the stage lights have replaceable using colored plastic (I think these are called "gel" in industry). You should be able to buy a red one for almost nothing and cut hundreds of these red lenses beyond. Or keep the rest if you ever break a tail light!
Mini Maglite
Mini Maglite











