Air bladder and air bladder set

An air bladder for use in a vehicle seat, the air bladder comprising:

• an air chamber configured to be filled with air;
• a sheet member separating the air chamber from an exterior;
• a communication hole formed in a central portion of the sheet member, the communication hole allowing communication between the air chamber and the exterior;
• and
• at least one guide portion located adjacent to an air chamber side of the sheet member, the at least one guide portion being configured to guide air that flows into the air chamber from the communication hole toward an outer periphery of the air chamber,
• each of the at least one guide portion being formed as an elongated protrusion on an interior-facing surface of the sheet member, the interior-facing surface facing the air chamber, and
• the elongated protrusion extending in a direction inclined with respect to a radial direction of the communication hole.