Material of Construction: Body, damper plate and shaft is made of PVC. Locking quadrant and fasteners shall be made of stainless steel. 

Temperature Limitation: Adjustable Damper recommended up to 140º F.

Application: Designed to operate in ducting where highly corrosive air is present.
Designed to fit round schedule 40 PVC ducting or other construction
materials as specified by the dimensions listed for each model damper.

Features and Benefits:

• All internal parts are plastic
• Furnished with locking quadrant damper allowing for permanent position set
• Allows for less than 5% airflow restriction
• Offers an approximate 95% seal
• 90º damper plate operation
• Can be installed either vertically or horizontally
• Has bell end sockets and shall have minimum socket depth of 2 inches or more except on the 4 inch model which will be 1.75 inches
  

Metric Dampers:

• AD125: 125mm PVC Duct 
• AD160: 160mm PVC Duct
• AD200: 200mm PVC Duct
• AD250: 250mm PVC Duct
• AD315: 315mm PVC Duct

Metric Adjustable Butterfly Dampers Submittal Data and Specification