While this is an existing HPI Racing option part, the hump battery pack can be used in the Hellfire taking up less surface area in the battery box than the factory flat 5-pack. With the remaining space in the battery box you can make use of smaller racing receivers and place your receiver in the battery box for added protection.

#87022 Foam Tape 25x60mm

Also in the photo you see #87022 Foam Tape 25x60mm used to support the battery. The Foam Tape pack comes with 3-pieces of 25X60mm. HPI Racing recommends using one piece on each side of the battery and cut one piece in half and place one piece on the bottom of the bottom side of the battery and the other half on the battery box lid.