Aperture
Max	-	100.0 mm
Min	-	Approx. : 5.0  
		(Before blackout shutter engages ) 

Construction
Body	-	Brass
Cover   	-	Aluminum ( Pinned  )
Leaves  -   	FS155BR  x 18 Incoloy
Finish	-	Black Stove Enamel
Handle 	- 	85.0 x 16.0 mm Steel
Mounting -	3 x M2 Cover Mounting Holes