When using two batteries, the grip will automatically switch to the second battery if the first becomes depleted. Switching does not interrupt camera operation.
Remaining power indicator
*In the Box:
1x Brand MB-D10 Battery Grip
1x Battery Holder for one Li-ion Battery
1x Battery Holder for eight AA battery
2x Brand EN-EL3E Battery
1x BL-3 Battery Chamber Cover
1x User manual
Two years warranty
* Work For D300 D300S D700 D900 SLR Digital Camera