The single-action, spring-return hydraulic power cylinders are small pistons that can be used alone or combined. They offer tremendous force in a small, easily mounted package that can be used in any altitude and require only a single inlet port. They are often grouped together by a common manifold to provide as much force as needed for the operation. For a relatively small volume of oil, they provide exceptional exerting force, and are generally the best choice if stroke lengths are short.