Column level indicators in transparent polyamide-based technopolymer, black glass fibre reinforced polyamide-based SUPER-technopolymer protection frame, screws in polished zinc-plated steel or in AISI 303 stainless steel or in SUPER-technopolymer, nuts and washers in polished zinc-plated steel or in AISI 304 stainless steel, NBR synthetic rubber or FKM O-ring packing rings and white lacquered aluminium contrast screen.