Constant flow circular regulator to balance ventilation and air conditioning installations. Characteristics: -Circular dampers, without external power source. -Factory preset flow rate, adjustable by means of a high-precision external mechanism. -Compact laser welded galvanized steel construction. -Differential pressure from 50 Pa to 1000 Pa and air flow from 3:1. -Operating temperature from -30ºC to +100ºC.