Single-rod cylinders are cylinders with a one-side piston rod and thus with a large piston area for extension and an area for retracting that is reduced by the piston rod area.
Single-rod cylinders are also called differential cylinders, which, strictly speaking, is only correct if the ratio of the working areas is 2:1. Since this is often not the case, the term single-rod cylinder is more appropriate.
Adding air filters permits the use of single-rod cylinders as single-acting cylinders - for pushing or pulling.
Single-rod cylinder