Can I just say how great I think the Black Box and Tuxedo from Al Jacobs are? Had them for a few weeks and used them on 3 events now. They work like a charm. The first wedding I did with it I used the Tuxedo for pre wedding and the ceremony, them used the black box for the reception. If anyone is in need of battery packs for their flash, it's really hard to beat them for the price.