OK Mlinky, How about the 510? Seems this window of transparency can't exist with a 510 as the element is sheathed by metal casing. I guess there's really no option for a visual with a 510 without looking down the tip....Did I just answer my own question! LOL
For checking to see if you are squonking correctly, you don't look into the atty, look at the little holes in the bottom of the catch cup and squeeze only until you see a tiny bit of juice peek through.
You can see juice in the 306's because they are almost covered by juice when they are properly juiced. If you are watching for juice in a 510, chances are the atty is flooded.
