SPD910 is a relative and differential pressure switch suitable for use with air and neutral gases, for the monitoring of air ducts, filters and fans within ventilation systems. Available in 4 models to cover a range from 20 … 2000 Pa with high adjustment accuracy. Each model has an adjustable dial with clearly marked individual scale for easy adjustment of the switching set-point. Supplied complete with 2 m (6.56 ft.) clear tubing plus 2 plastic pipe duct connectors and screws.