A linear compressor unit including a reciprocating magnet driven by an electromagnetic alternating field. The magnet drives a piston reciprocatingly in a cylinder in a module casing, which casing also encloses a buffer volume. The cylinder is mounted in the casing so that it can oscillate. The cylinder includes an inlet opening coupled to an inlet passage in the module casing lying opposite to one another but without making contact with each other and forming a passage to the buffer volume. At least one restrictor element is located in the passage to dampen sound of the unit.