"HYP Air Balance ventilation valve DN 50: – Prevents the formation of negative pressure in the Sewerage system installation. – ensures that lock feature Water Made in the Siphonen wont dry out. – Prevents the escape of unpleasant odours and gases from the Sewerage system. – Eliminates the problem from gurgling in the line pipe. – Maintenance-free ventilation valve, especially suitable for passive and energy saving with buildings. – risKanten roof Durchdringungen including for Flachdächern or as well as a roof windows are no longer necessary. – No cold spots, making it no dangerous condensation formation on tubing. – 100% airtight with HYP Air Balance System. – Made in the EU. – CE tested and approved to standard EN 12380. – Temperature resistant from 0 to 60 Celsius degree (32 to 140 °.