The pixel td-384 battery pack for sony speedlites provides you with sufficient power for your sony speedlite. The td-384 is powered by 8 aa batteries (not included), which are split into 2 groups of 4 batteries (see photo 2). by having the 2 different groups of batteries, the td-384 is able to provide a charge time of 1.72 seconds per flash, which is much higher than that of the comparable battery packs. tests have been done on this battery pack and results indicate that the td-384 can produce 546 flashes at full power (tested with 1 flash per 30 seconds with 4 duracell batteries). The td-384 weighs 200 grams (without batteries) and is 170 x 72.5 x 25 mm in size. the td-384 is supplied with a screw, enabling you to attach the battery pack to the bottom of your camera. further, the td-384 is supplied with a protective case, which can easily be attached to your belt for freedom of movement and security. If you wish to mount your td-384 and camera onto a tripod, the tmb-20d camera bracket is essential. the tmb-20d can be found in the optional accessories tab below. The td-384 is compatible with the following sony speedlites: sony: hvl-f58am, hvl-f56am, hvl-f60am