Performs well. But its very disappointing that theres no battery life indicator. Feels like spending top dollar on very old tech. But if you need it you need it, and it gets the job done.

It is a must have for wedding photography as it powers the flash bursts and therefore reduces your recycle time enabling you to get the shot at the correct exposure. When it works it is 5 out of 5 stars but they seem to be prone to failure.

I use the battery pack for christenings, birthdays, family get-togethers, and all those events that go on forever. The battery pack has never let me down. It powers my SB-910 Speedlite and it stays cool and operational - never overheats. I took 21 pics of two toddlers in less than a minute.

Works like a charm. Not concerned about my speedlight stalling on me. Used it on a couple of shoots and worked as expected.

This battery pack works great with my Nikon SB5000 speedlights. It's helpful in a pinch if I don't have a more substantial pack such as an Al Jacob's Black Box or Quantum pack handy. It's cheezy plastic construction makes it something I would not rely on without a backup.

I needed this! My SB900 flash & SD-9 battery pack work great together.Faster & greater power flash output,without heating up the unit. Speedy recycling & compact. Wished I had purchased it sooner!

Loving this thing - I take it to nearly every shoot to extend the batter life of my on and off-camera flashes. I went from changing flash batteries every hour or so to not changing them at all for 4 hour events!

This power pack provides consistent output and excellent flashes. I have had three continuous 4 fps shots with flashes. Flashes came on each and every shot. However, this SD9 power pack is used only to shorten recycle time.

This is a nice option for the event photographer who needs quicker recycle times and extended flash usage. It would be nice to have a rechargeable pack option, though.

Great addition to the SB-900 or SB-910. Instant recycling and I can go all day long. It comes with a holder that can be clipped to your belt. What I did is take advantage of the Kirk L Bracket on my camera, a Kirk plate, and the screw on part of this unit.