Amazon.com : Fotodiox Pro Softbox, 24"x36" (24x36 in) with Speedring, for Profoto Compact lights series D1 250 W/S, D1 500 W/S, D1 Air 1000 W/S, D1 Air 500 W/S, Pro Series Acute B 600 W/S, Pro-B 12000 W/S, Acute 2-D4 Strobe Flash Light, Soft box, Speed Ring : Photographic Lighting Soft Boxes : Electronics