The ring stretching tool is similar to a sizing mandrel. It is mounted vertically with engraved sizes in order to determine the ring size. The difference is that the mandrel on the stretcher is split into sections. So, when the arm is pulled forward the mandrel expands and slowly enlarges the size of the ring. Place one hand onto the ring stretching tool to steady it (if it is not mounted), and then pull the arm forward so that pressure is applied to the ring. It is suggested that the operator makes small increases at a time, so that it does not damage the ring and that the exact size is obtained. It is important not to exceed the size that you are trying to obtain.  Continually check the ring using a ring stick until the size that you are trying to obtain is reached. It is also important to take off, rotate and flip the ring so the enlargement is symmetrical. You may need to repeat this process a few times. The stretcher is most often used for bands and not for rings with stones or ones that may have been previously sized. Otherwise, it may cause the ring to split if too much pressure is applied to the seam. It is also possible to damage a setting so it is not suggested to use this for this stretcher in this instance.