CowboyStudio 60-Inch Octagon Grid Softbox for Alien Bees (60 INCH OCTA GRID-AB) Diameter of the octagonal box is 60 inches Speed ring ideal for use on our high watt strobe heads, the speedring fits AlienBees strobe lights Two diffuser panels allow you to easily adjust the softness of the light Case is black and easy to pack Grid is detachable to use as a standard softbox - Not included with this purchase.