-Designed for 4pcs AA battery.
-Compatible with Flysky receiver & servo tester.
-Battery NOT included.
-You will receive 4pcs 4 cells aa battery holder.
If you have any problem, please contact seller as follow: click " DIYmalls-UK"(you can find "Sold by DIYmalls-UK" under Buy Now button), in the new page, click "Ask a question".