The fact that they are an imported unlabeled class-four 1.5-watt blue-green diode laser without approved safety interlocks, guarding or regulatory approval. That was the consensus of two internet experts one of which threatened turn Amazon into the FDA and FBI then turned around and threatened me via private message with direct legal intervention if I continued to operate the lasers without the --
Know what? It's pointless internet drama. Aside from that paragraph, it won't be mentioned again.
Now here are the facts:
It is an unmarked 1.5 watt diode laser without a safety interlock. What I did was build plywood around it on three sides, then bought filters for the front so I can view the beam safely. I wear goggles and a glove when focusing it in "weak light" mode, and put them in a separate room. My wife runs them with me, she's a welder by trade she's familiar with light hazards from her work. I don't allow the teenager in the laser room unsupervised, our safety-goggle policy is as strict as the goggle policy in the comic-strip.