The expanding arms are laser welded to the screw body. Laser engraved directional arrows on the MIM® body. It is a device for the rapid expansion of the palate that allows you to get a widening of the single anterior sector of the maxillary arch, still maintaining the expansion at the molar level. arm:1.5mm body:16mm expansion:11mm one screw turn:0.8mm **For further product information , please contact Chat support**