They are in front of the elevators at an outdoor multi story parking garage around my area. That's all I wanted to share, thanks.
Given that they have to be a distance apart relative to the wavelength they're emitting, I'd guess about 10 times larger than a single emitter with the same output. However, because it's able to create beams with cross-sections similar to the profile of its targets, I'd argue it could just have a lower output and resolution with similar performance to a single emitter for half that. Those are wild guesses. Hopefully an engineer is lurking around here somewhere.