Those are made out of foam. Unsure of the stability/durability. I did not make those.
Perfect Circle will be carrying some of my cheeks soon.
Another satisfied bamboo customer below. He also added that he had his OT fit in the bottom row easily by doing the following:
"I just took the lower screws holding the MD out, rotated it a little, put the cables in and then rotated it back and fastened the screws again."
I have setup all batches moving forward to have circular vent holes for A4 users. They will be on the top and the bottom so the user can choose to move their units around freely.
Thanks for everyone's continued support.