Flexible fluid reservoir system

A fluid reservoir configured to attach to a pump head, the fluid reservoir comprising:

• an attachment configured to engage with a pump head socket, where the attachment comprises threads at an attachment outer surface portion;
• a fluid reservoir outer body having an interior surface and an exterior surface;
• and
• a fluid reservoir inner body disposed at the interior surface, wherein:
• the fluid reservoir inner body is configured to store fluid,
• the fluid reservoir outer body and the fluid reservoir inner body form a single piece fluid reservoir,
• the fluid reservoir inner body comprises a rigid closed end and a flexible sidewall,
• the flexible sidewall is configured to fold onto itself when the fluid is dispensed from the fluid reservoir inner body, and
• the rigid closed end is configured to move upwards longitudinally towards the attachment when the fluid is dispensed from the fluid reservoir inner body.

A fluid reservoir configured to attach to a pump head, the fluid reservoir comprising:

• an attachment configured to engage with a pump head socket, where the attachment comprises threads at an attachment outer surface portion;
• a fluid reservoir outer body having an interior surface and an exterior surface;
• and
• a fluid reservoir inner body disposed at the interior surface, wherein:
• the fluid reservoir inner body is configured to store fluid,
• the fluid reservoir outer body and the fluid reservoir inner body form a single piece fluid reservoir,
• the fluid reservoir inner body is 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 to a length that is twice a fluid reservoir outer body length,
• the fluid reservoir inner body comprises a rigid closed end and a flexible sidewall, and
• the rigid closed end is configured to move upwards longitudinally towards the attachment when the fluid is dispensed from the fluid reservoir inner body.