The DASL shutoff damper with EPDM gaskets at both flange connections is designed for cladding with up to 50 mm thick insulation. The DASL shutoff damper is a good choice when the ductwork closure does not have to be fully airtight. The damper closure position can be read on the 0° to 90° dial of the control handle. The damper closure opening ratio can be fixed with a screw.