This is the 230x300mm Lithium Polymer Charging Safety Bag from Ultimate Racing, and is intended to reduce the chance of damage or injury in case of a LiPo fire.
Due to the volatile nature of Lithium chemistry batteries, charging bags such as this Ultimate LiPo Safety Bag are required by many tracks, flight clubs, etc.
Dimensions: 230x300mm
WARNING:
Never leave charging battery unattended.
Always ensure the battery is on a non-flammable surface.
Ensure flap is sealed while charging.