Battery holder for quadcopter

This is a battery holder for quadcopters. This holder allows a solid mount of the battery, so it doesn't wiggle during the flight, and it allows to do acrobatics without losing the battery in air.
I use it for the quadcopter with a frame Q450 V3 from Hobby King, but it can also be mounted on other frames. To mount this holder you can use 4 M4 holes on the bottom of the holder. To fix the battery in a holder one can use standard battery straps. Battery holder ca be mounted either on top or on t