This light has 6 red LEDs plus a red filter and runs off of 4 AA batteries. The light is bright enough to read with but is not overly bright. It has a strap to wear the light around your neck, but I rarely do so. I prefer a light mounted on the brim of my cap when working, but when reading this light is great. It has two positions to illuminate the right spot.
These lights are also available from Amazon.
As I said earlier, when working at the scope I like a red light mounted on the brim of my cap. I've tried several such lights and the one I like the best is the Bushnell H65L. This little light has red and white lights, as do many such products. However what I like about this one is it has separate switches for the red and white lights and the red light switch is on the Right ! So I can avoid blinding myself or others at star parties by hitting the wrong switch. Even I can remember Right = Red.
The light is small and lite so it won't weigh down your hat.
The light also tilts so you can point it directly at what you are working on.
I'm sure these are available at many places but I got mine at Walmart.
The last light I'll share is one that my wife picked up for me from Amazon. These flexible neck, clip on, red lights are small and very flexible so you can position the light right where you need it.
I do find the illuminated spot to be quite small so to read a star chart I have to move the light around. For reading star charts or books I prefer the larger 6 LED light discussed above, but I'm sure I'll find use for these as well.
If you are in need of a red light, give one of these products a try I think you will enjoy them.