The stand is a Manfrotto, the umbrella holder with stud is a Dotline, and the umbrellas are Westcott. All very cheap from
Midwest Photo Exchange New and Used Photographic Cameras, Lighting, Printers, Medium and Large Format. I ditched the aluminum 'dead shoe" and screw the stud right into the little base that came with the flash:
I use the 580 as a master for two 430 slaves. I have shoot thru and silver bounce umbrellas.
