This is the Large LiPo Safety Sack from Venom. Part # VNR1642

Charging batteries is now safer than ever with Venom updated Battery Safety Charge Sack. Not only have we included high temperature fireproof thread, but Venom has also incorporated snaps to the closure flap to better help contain fire and debris in case of a catastrophic failure. Made of flame resistant material, the Venom Safety Charging Sack will help protect you and surrounding areas from possible fire damage but does not eliminate the risks inherent with charging and handling LiPo batteries. Always follow the safety and use instructions provided with your battery and charger in addition to using this product. Use the safety sack while charging, storing or transporting your batteries.