i12,i15,i18—Signify the transmission ratio of movement's shaft gear which is xx.
H—Signify the vertical dimension of reversed assembling movement's needle pivot to Mounting holes of attachment.
B—Signify the center distance of reversed assembling movement's two mounting holes.
L—Signify the length of needle pivot (which means shaft gear).
e—Signify the length of needle pivot over the splint