The visors are components mounted on pressure or vacuum vessels, in order to visualize the mixture of solution and resin (ion mass exchange) in order to control the level and turbulence in its regeneration process (aeration / regeneration / washing). The visors are made of plexiglass plates with thickness between 20 and 50 mm. Working conditions: 1. Working fluid - water, air and solutions of max. 15% of H2SO4, HNO3, HCl, NaOH, NaCl, NH3, Na3PO4, etc. 2. Maximum working pressure: 10 bar 3. Hydraulic test pressure (at the same time with the vessel): 12,5 bar 4. Working temperature range: 5º - 60º 5. Safety coefficient: 3 6. The visors must not be used for: oil products, toxic fluids, lethal or explosive substances