Godox SA-06 Iris Diaphragm The Iris Diaphragm for Projection Attachment from Godox slips into a slot in the attachment and allows you to vary the size of the projected circle of light, as well as focus or diffuse. Iris Diaphragm for Projection Attachment from Godox slips into a slot in the attachment and allows you to vary the size of the projected circle of light, as well as focus or de-focus it. Product requires SA-P1 Projection Attachment. Dimensions: Outside diameter: 72mm Thickness: 4mm Inside diameter: 47mm Outside diameter including handle: 95mm