The proverbial box of fans. Sans the fans.
Talking about fans, if the water cooling blocks are square, why are they pegged against a round hole? Wouldn't it make more sense to
have a different back plate on the Sierra?
Going off the renders, they use a push-pull fan arrangement on the radiators, so having square holes wouldn't help and would take away more aluminum that stiffens the case.
The fans are round. Technically, the blades of the propellers arent round, but when rotating they move in a curiously circular pattern ;-)