More compact than hydraulic cylinders with external tie rods, these cylinders have a round body that fits better into tight spaces and have a more streamlined appearance. To further minimize their footprint, they operate without an air cushion. These cylinders are double acting, meaning they both push and pull loads. They use two hydraulic ports, one to extend the piston and one to retract it. Because the piston is magnetic, these can be used with sensors (sold separately) to indicate piston position.