Interesting, this appears to be a silicon-graphite powercell which utilises a thermoelectric effect. Therefore ambient heat is used create electricity. In some sense of the word, this "works", but is not really free energy - since the energy is provided by whatever is heating the ambient air.
The products offered by Quanta Magnetics are expensive, and seem to have unnecessary "woo" features added possibly to add cost, but also appeal to free energy crowd (e.g. a Bedini "generator", "Schumann Resonance").
The problem with this type of technology is that is impractical because of the cost per Watt, and doesn't scale. You can extract 50W from a typical room without noticing it, but if you tried to extract kW then it becomes huge and expensive, and also of course you need to provide additional heating.