S: for 30mm in height within the metal frame，

M: for 32mm in height within the metal frame，

L: for 34mm in height within the metal frame

* Clip without frames， oh， if there is no pro-myopia， please do not shoot! . .

* Although this clip is metal frame dedicated， but not all metal frame are applicable， for the beam position is too high (with the frame on the side of the height difference of 3mm) does not apply， the beam shape is too strange to choose!

* General metal frame， it is recommended to choose the size of the clip， clip height higher than the height of the frame more than 2mm， clip width is greater than equal to the width of the frame