The CFPack, or Construction Foam Backpack, is a chest piece from IndustrialCraft2 that can store CF Pellets for use with a CF Sprayer. Each pellet stored within the backpack provides two sprays instead of one. It is refilled at a Canning Machine and relies on CF Sprayers to extract its foam. While equipped and containing pellets, any CF Sprayer the player uses – including empty ones – will draw from the backpack's supply. Unlike a BatPack with an electric tool, the CF Backpack will not recharge its CF Sprayer.
The full capacity of the CF Backpack is 129 CF Pellets but each pellet provides two uses instead of one; this equates to 258 sprays of Construction Foam when filled. In contrast, the traditional CF Sprayer can only store 16 CF Pellets and provides a maximum of 16 sprays.
One penalty the backpack suffers is that it can only be refilled at a Canning Machine. To refill the CF Backpack, the player must place it in the lower slot of the Canning Machine's GUI and place the refill CF Pellets in the upper slot.