You can't use white light torches when you're trying to use a Telescope as the white light causes your eye to dilate. Using a red light you can change telescope settings or read a star map and then go straight back to viewing without any waiting period for your eye to adjust to the light conditions.
Overview:
Two torches for the price of one!
You choose red light or white light with the flip of a switch.
Brightness wheel sets the desired intensity, from dim to bright.
Red for while at the telescope
White for increased brightness and visibility when packing up