Thanks. Guess it's time to pinch some more pennies.To the best of my knowledge, Altinay is the only one that identifies the pipes that are made from "translucent" blocks (I believe they coined that term). At least I've never seen any other seller display the distinction. You may find one elsewhere, but it's difficult to tell from a pic whether it's that type of block.
More recently I noticed Altinay also started grading the translucent blocks as A, AA or AAA. Some kind of quality distinction, but not sure exactly what it represents.