This rugged cylinder design is used for the single hitch leg of the combination horse trailer / travel trailer RV units. This design has been used for several years by the Sooner Trailer Manufacturing Company of Oklahoma. This cylinder is 2 1/2" bore X 16" and 3" X 18" stroke design with a 3/4" inside diameter cross tube on the cap (blind end) and a 3/4" cross hole drilled through the piston rod end. The rear port is a #6 SAE O ring boss and the front port is a #4 SAE O ring boss style. This basic design has been in production since 1999, with approximately 5,000 shipped from stock.