Mode usage occasion Standard Model used in the occasion for connecting the steel bar in normal situation Different Diameter Model used for connecting the steel bar in different diameters Flared Model used for the steel bar which was hard to match Positive And Negative Screw Thread Model Used in the occasion when the steel bar in the two sides both can not be turned but the lengths can be adjusted. Locking Nut Model Used when the steel bar can not be turned, then it turns the splicing coupler to join the steel bar and then lock the splicing coupler with the locking nut.