Illustration of the M5 mirror and cell support structure that will be used on the European Southern Observatory's Extremely Large Telescope (ELT). The support cell structure will ensure the stability of the flat, 2.7m x 2.2m, elliptical M5 mirror. The M5 cell includes a fast tip-tilt system for image stabilisation. Along with the M4 mirror, the M5 mirror compensates for perturbations caused by the telescope mechanisms, wind vibrations and atmospheric turbulence, forming part of the ELT's adaptive optics system. The support cell structure was designed and manufactured by SENER Aerospacial.