Galvanized steel pressed reduction pieces, with rubber sealing.
Maximum diameter 315 mm.
Connection pieces until Ø200 with airthightness class D to EN 12237, connection pieces bigger than Ø200 with airthightness class C to EN 12237. The airthightness class is also determined by the mounting on the construction site.
Explanation :
RDG = Type of reduction
250 = Largest diameter of reduction
200 = Smallest diameter of reduction