Here's what the air intake system looks like on an EKO 60. The yellow air adjustment knobs are a modification. Just two wire nuts screwed and glued onto the ends of the adjustment screws. It's a lot easier to play with the air adjustment if you can grab it with your fingers, instead of fiddling around with a screwdriver. Note that there's nothing fancy or sophisticated here. The two sliding plates in the upper corners allow air into the firebox, I believe. The air supply to the nozzles is delivered through the round pipes. It is regulated by the steel disks, which are adjusted with the (now knobs on the) threaded rods. Then there are the adjustable baffles on the blowers. I believe the EKO 25 and 40 have one nozzle and one blower. The 60 has two of each, and I believe the 80 does as well, though it might have 3.