No limits to the invention of jokers! Bravo!

This is of course aerobatics and it seemed to me that there are electric motors, and what is the capacity of the battery? I would like to know what is at the ends of the blades and for what? Years ago, 60 was interested in technology, but there was not so much literature, and there are simply no words to give the highest rating to the device.
As for me, I'm on the tailbone.