Sorry Steve this is the best picture I can find on my laptop, (I'm working in Port Angeles this week)
These are 2" to 1.5" reducers. I held the 1.5" part with chanel locks, and cut 2 cuts on my chop saw side by side. Then rotated and did it again. This way I got 1/4" slots, and about 2.5" long. Inside the reducers there are vanes that direct the water flow just right. They are not that quiet, unless you have enough water, then they are not bad. But they are great for surface skimming and handle full 1/5" flows.
These were the original screens on 90 elbows, the 2 1.5" units would only take about 500-600 GPH before they would over flow the tank. Now I run about 1000 GPH with lots of room to spare (Using MAK4, will try MAG18 soon) But they were dead silent, even when I cut out every second screen. They did not provide good surface skimming.
Lee