In aviation, a drop tank (external tank, wing tank, or belly tank) is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often jettisonable. External tanks are commonplace on modern military aircraft.
All Bottle Wraps are sewn with matching color thread and black bias. Made from a custom fabric called SRF, a foam with polyester laminated to both sides. All Bottle Wraps can be flipped inside out for an all black cover. Newer generations will have black thread on the inside.