Can I see the IR (infra-red) GLO-TOOB with my naked eyes? I cannot see the IR unit working, do I need special equipment, or is it faulty?

No, the IR GLO-TOOB can only be seen with NVG (night vision goggles/gear), or infra-red viewing equipment. (Point your digital camera, or video camera at the activated IR unit, and you should see it working on the display screen of your camera/video camera, if you don’t have NVG!)

What is the difference between the IR 875nm and the IR950nm GLO-TOOBS?

The difference between the two IR GLO-TOOB is only the wavelength frequency they run at; 875nm and 950nm. Only the latest tech. NVG (night vision goggles/gear) will be able to see the IR 950nm wavelength. While older generation NVG (generation 3 and below, typically) will be able to see only the IR 875nm and not the IR 950nm GLO-TOOB.