PN#100131  SKU#13379  3-1/2″ Air Cylinder. Stroke: 6.68″. Style: Tailgate Cylinders. Diameter: 3-1/2″. Retracted Length: 13.60″. Extended Length: 20.28″. Cylinder Type: Push/Pull. These cylinders can be used in a wide variety of applications and conditions and can take the daily abuse associated with typical tailgate applications. 3-1/2″ Air Cylinders at 100psi have a thrust of 962lbs and a draw of 918lbs.