Abstract: Device which is to be placed in the uterus to which certain substances such as metals, metal ions, hormones or therapeutic substances which are to be effective in the uterus for a certain time, can be attached. The device comprises a stem with resilient or flexible arms projecting on either side of the stem near or at one extremity thereof, and the extremity of each of the two arms is bent through an angle greater than 90.degree. so that the extremities point towards the stem. The arms are thus built up of three parts, i.e. a first part and a second part or extension, and a bent piece between them, the three parts of each arm together form an arrow the legs of the arrow being formed by first part and the second part or extension of an arm, the parts being compliantly connected to each other by the bent piece. The direction of the first part near the bent piece points horizontally or upwards.