the other evening on the news their was a restaurant that had a door to the rest toom that you could see through till the door was closed and locked. they said it took 110 voltsto activate. they stated that it cost 13000.00 dollars. did not state who made it or any thing else.
The 3M technology is very costly. Refr SPD also uses significantly lower voltage. I recommend people who want information on competive technologies to contact Joe Harary at firstname.lastname@example.org. with your questions. I have always found him very obliging and informed.
Other companies are trying to develop "glass" that changes but no one has the SPD technology. 3M has a product that is milky in color when not in the clear state, and has a slight haze even when clear. Another small company in Ohio is working on this also. Guardian Industries is also rumored to be trying to develop this technology, but again no one has the SPD as REFR does. It is my belief that "when" product does come on line and gets to the market place REFR and SPD technology will blow the rest of them out of the water. Enjoy the ride!!