Ok these two are a bit more esoteric, but quite useful in some situations.
Technically they are "square to rounds" a common shape in ducting Image may be NSFW.
Clik here to view.
The glass blocks are good for seeing the shape transitions, more so than the actual green blocks themselves ( a 1 to 1 square to round never renders well ) View attachment 11867
Technically they are "square to rounds" a common shape in ducting Image may be NSFW.
Clik here to view.

The glass blocks are good for seeing the shape transitions, more so than the actual green blocks themselves ( a 1 to 1 square to round never renders well ) View attachment 11867