Tianyuandifang

Tianyuandifang also called “ square circle ”
Note: it is most often do is change, change is round and square opening center on the center line,
If the left and right side of the eccentric: the need to draw a picture that is the face of the mouth, left or right?
If the upper and lower deviation: drawing is said for example high square or round round than high?
The general need to buckle into round buckle a round flange, round flange price for another operator, also can be matched to the newspaper.