for pressure and volume flow control in HVAC-Systems, casing made of galvanized steel, depth 180 mm, double-walled, insulation 30 mm mineral wool, inside sealed with special foam and sliding foil, one-sided connection rod, coupled in same direction, bearing made of brass, lamellas made of special aluminum-profiles, insulated with 50 mm mineral wool 60 kg / m3, horizontally arranged, one side rubber lip seal, lamella height 165 mm, physically free cross section approx. 59%, console for actuator, 90 mm deep, drive axle 15x15mm, reinforced design, air-tightness class 4 (casing class C) according to DIN EN 1751 and DIN 1946 T4, temperature-resistant from - 20 ° C to + 80 ° C, silicone-free, connection frame 30mm