A grease gun cylinder walled cartridge adapted for direct attachment to any of a variety of grease gun head constructions and grease pumping systems, wherein the cartridge wall can be of any color or completely clear and see through, wherein the grease column within the cartridge is pressured toward and through an inlet port in the gun head, which port opens on the section stroke of a piston mounted in said cylinder into a loading portion of a cylinder of the grease pumping system, and wherein the grease column pressuring means is ambient air pressure.

A fluid reservoir configured to attach to a pump head is disclosed. The fluid reservoir may include an attachment configured to engage with a pump head socket. The attachment may include threads at an attachment outer surface portion. The fluid reservoir may further include a fluid reservoir outer body and a fluid reservoir inner body. The fluid reservoir outer body may have an interior surface and an exterior surface, and the fluid reservoir inner body may be disposed at the interior surface. The fluid reservoir inner body may be configured to store fluid. The fluid reservoir outer body and the fluid reservoir inner body may form a single piece fluid reservoir. The fluid reservoir inner body may be configured to expand longitudinally when the fluid is filled in the fluid reservoir inner body and collapse longitudinally when the fluid is dispensed from the fluid reservoir inner body.

A fluid reservoir configured to attach to a pump head is disclosed. The fluid reservoir may include an attachment configured to engage with a pump head socket. The attachment may include threads at an attachment outer surface portion. The fluid reservoir may further include a fluid reservoir outer body and a fluid reservoir inner body. The fluid reservoir outer body may have an interior surface and an exterior surface, and the fluid reservoir inner body may be disposed at the interior surface. The fluid reservoir inner body may be configured to store fluid. The fluid reservoir outer body and the fluid reservoir inner body may form a single piece fluid reservoir. The fluid reservoir inner body may be configured to expand longitudinally when the fluid is filled in the fluid reservoir inner body and collapse longitudinally when the fluid is dispensed from the fluid reservoir inner body.

A fluid reservoir configured to attach to a pump head is disclosed. The fluid reservoir may include a fluid reservoir outer body and a fluid reservoir inner body. The fluid reservoir outer body may have an interior surface and an exterior surface, and the fluid reservoir inner body may be disposed at the interior surface. The fluid reservoir outer body includes an open bottom end. The fluid reservoir inner body may be configured to store fluid. The fluid reservoir inner body includes a rigid closed end and a flexible sidewall. The fluid reservoir inner body may be configured to expand longitudinally when the fluid is filled in the fluid reservoir inner body and collapse longitudinally when the fluid is dispensed from the fluid reservoir inner body. The fluid reservoir inner body is configured to expand beyond the open bottom end of the fluid reservoir outer body.

A fluid reservoir configured to attach to a pump head is disclosed. The fluid reservoir may include a fluid reservoir outer body and a fluid reservoir inner body. The fluid reservoir outer body may have an interior surface and an exterior surface, and the fluid reservoir inner body may be disposed at the interior surface. The fluid reservoir outer body includes an open bottom end. The fluid reservoir inner body may be configured to store fluid. The fluid reservoir inner body includes a rigid closed end and a flexible sidewall. The fluid reservoir inner body may be configured to expand longitudinally when the fluid is filled in the fluid reservoir inner body and collapse longitudinally when the fluid is dispensed from the fluid reservoir inner body. The fluid reservoir inner body is configured to expand beyond the open bottom end of the fluid reservoir outer body.