Abstract: The capsules or other products (1) are fed by a vertically arranged tube-shaped conveyor (4, 5, 10, 11, 12, 112, 13) in single file and taken up one at a time by a tangential wheel (16) which is fitted with reference teeth (18), with each tooth supporting one product, and has suction holes (19) to retain the products. When the products are about to reach a position above suitably shaped associated weighing heads (24), the suction that holds them against the wheel is cut off and the products fall, positioning themselves correctly on the heads, aided in part by the halting action exerted by the teeth in front. The products deposited on the heads are weighed and are then discharged by the pushing action of the wheel teeth (18) which place the next product on the heads. A chute (25) collects the products ejected from the heads and a deflection plate (26), controlled by the central processing and control system (32), separates products of the correct weight from those to be rejected.