Abstract: A conveyor for testing successive plain or filter cigarettes or other rod-shaped smokers' products having non-circular (such as oval) cross-sectional outlines employs a rotary drum-shaped conveyor for sidewise transport of smokers' products toward, through and beyond a station where the products are tested by streams of a gaseous fluid entering the products at one axial end and issuing from satisfactory products at the other axial end. The end portions of the products are sealingly received in complementary sockets of elastically deformable sealing sleeves which are connected to their tubular fluid-conveying carriers in a manner to ensure that each sleeve remains in a selected position for optimum testing of the products.