I have a ptec byte that has most of the mentioned features, weighs 2.17 ounces with batteries, and runs on 2 AAA bats. it has a head band, points up or dow - adjustable - red LED, white lower power or higher power LED. Its got a sealed switch.

In 1961 I worked at American Microsystems in Sunnyvale, later a superfund clean up site, where I was on the integrated circuit design staff. I was looking at a chip under a microscope while it operated and it occasionally gave off a small flash of light, which I commented on, and later we made the first LED
Jim