The SSDD-OE is an optical smoke detector for mounting on all duct types. it reacts on visible and invisible smoke particle sand can therefore detect fire at an early stage.
The aluminium Venturi tube is mounted in the duct through a hole , 30mm diam. The tube can be shortened to fit all duct sizes. The sampling tube is included in the price of the SSDD.
The detector housing has a window giving a clear view of the flow indicator and the alarm LED.