PLATO (PLAnetary Transits and Oscillation of stars) is the ESA Medium size dedicated to exo-planets discovery and cataloguing, adopted in the framework of the Cosmic Vision 2015-2025. The PLATO launch is planned in 2026 and the mission will last at least 4 years in the Lagrangian point L2. The primary scientific goal of PLATO is to discover and characterize a large amount of exo-planets hosted by bright nearby stars. The PLATO strategy is to split the collecting area into 24(+2) identical 120 mm aperture diameter fully refractive cameras with partially overlapped Field of View delivering an overall instantaneous sky covered area of about >2100 square degrees. The opto-mechanical sub-system of each camera, namely Telescope Optical Unit (TOU), is basically composed by a 6 lenses fully refractive optical system, presenting one aspheric surface on the front lens, and by a mechanical structure made in AlBeMet. In this paper we will update on the current working status of the TOUs.