I don't quite know how to explain this in a succinct manner.
LoadSaveBlock(50807);
Let's start with the basics
-This is a glitched wall type
-It is not visible
-This wall has properties similar to fan, detector wall and liquid permitting wall in that falling particles (especially powders) generate a higher "amount" of velocity...
Resulting in (if enclosed) a simulation where if you drop heavy powders they generate stupendous amounts of velocity...