The assortment of special expansion screws proposed by Leone derives from over 30 years experience in the manufacture of expansion screws. Screw selection ranges from the Pagani classical fan-type screw, to the Bertoni three directional ones, up to the kit for construction of the Twin Wing class II corrector. The special purpose expansion screws are made of biomedical
stainless steel with a mechanical tolerance superior to 1/100 mm. The thread parts are absolutely smooth and ensure great sturdiness, good friction and prevent any unwanted turning-back.