Fotodiox 10SBXPPT70OT Pro Octagon Softbox 70-Inch with Speedring for Profoto Compact Lights Series D1 250 , D1 500 , D1 Air 1000 Strobe Flash Light, Octbox, Speed Ring and Soft Box
The Fotodiox dedicated speedring is specifically designed for your strobe light to fit standard softboxes both rectangular and octagon boxes. It has a outer diameter of 7 5/8", fits 1/4" standard rods. It fits all Profoto Strobe.