The presentation summarizes the tests of the SCT prototype that has been built and tested in the Instituto de Astrofísica de Canarias (IAC) facilities. The objective of this work was to investigate the system performance providing laboratory results to reinforce the validity of the proposed solution, focussing on the most critical performance characteristics of the mechanical design. The Scale Changer is a turret to switch between 4 scales + Pupil Imaging (5 positions), positioning one of the four mirrors at the optical beam or leaving the passage of light free (for selecting the 10x10 scale).