So you have to have a mixture of mercury discharge. And in those days, tungsten lights, now you do LEDs, but tungsten lights. So tungstens are not 3,500 Kelvin, so you have to put color filters into… And so basically, you have a mixture of mercury discharge, which are the robust sort of general lighting. And then you have tungsten, which are spotlights, which you light up waterholes, salt lakes, feeding platforms and things like that where the animals were hanging up. And I think that was basically the guts of the new stuff that we had to learn. And we had to learn how to design with using darkness and brightness, but it’s not that difficult. And unfortunately, people to this day in zoos who’ve tried to do it can’t seem to get it.
