A bag or pack for transporting material, which may include air tank bottles, rope, and/or other firefighting gear. The bag may be used in multiple different ways, but may be especially configured to rest on top of a primary air tank worn by the user and to avoid falling between that tank and the user's back. Pockets in the bag may allow the user to install bottles in an upright or inverted configuration, which may aid the user in quickly determining which bottles are usable. Bag may free up the user's hands, allowing him to carry extra gear and requiring further trips from a supply source to a staging area, which may be several floors up, e.g., in the case of a high rise environment.