I just got back from China and bought this from a street vendor. He claimed it was good for 5Km. pointer - Imgur
I can turn the lens on the end and make the beam larger. I can easily see the unexpanded dot on the top of a tower about half a mile away.
It quickly pokes holes in black styrofoam (dry erase board erasers), will put holes in plastic wrapper on a bottle, and when I bought it, he demonstrated it making a cigarette butt start smoking in a few seconds.
I don't have a meter to measure it, though I'm looking at the DiY plans here (how I found the site). Haven't tried a match or a balloon yet.
I can turn the lens on the end and make the beam larger. I can easily see the unexpanded dot on the top of a tower about half a mile away.
It quickly pokes holes in black styrofoam (dry erase board erasers), will put holes in plastic wrapper on a bottle, and when I bought it, he demonstrated it making a cigarette butt start smoking in a few seconds.
I don't have a meter to measure it, though I'm looking at the DiY plans here (how I found the site). Haven't tried a match or a balloon yet.