Walimex Pro Powerblock II External Battery for Nikon Camera Flashes SB28 / SB80DX / SB800 / SB900 black (Accessories)
after much deliberation I ordered this part of Walimex and it also came just one day before I wanted it well and test use. Have on the said day 400 photos shot with flash and the instrument will show no signs of slowing. All 4 green indicator lights