What kind of cylinder is this?

Cylinder: a cylindrical metal part that guides the piston to do linear reciprocating motion in the cylinder. Air expands in the engine cylinder, converting heat energy into mechanical energy; The gas is compressed by the piston in the compressor cylinder to increase the pressure.

The casing of a turbine, rotary piston engine, etc. Also commonly referred to as "cylinder". Application fields of cylinder: printing (tension control), semiconductor (spot welding machine, chip grinding), automation control, robot, etc.