A gynaecological instrument for delineating the fornix of the vagina during laparoscopic surgeries having a spring, which proximal end is securely affixed to a distal end of a solid ring and the distal end of the spring is securely affixed to a base. The extension of the base can be inserted into the head of the Valtchev® Uterine Mobilizer and locked in place. When the delineator is pushed toward the fornix of the vagina the solid ring is self-adjusting to the angle of the of the fornix and the length of the cervix. An elastic plastic ring is provided, for placing on the solid ring, in order to protect the ring and instrument which is used to open the vagina laparoscopically.