My husband's ring was loose on his finger and a friend suggested J & M Jeweler's to pick up a ring guard or insert so the ring would fit better. When I called, Louise suggested using their machine to 'shrink' the ring instead of the ring guard but she needed to see the ring first. Louise used this device to tighten the ring without cutting into the metal; my husband tried on his ring and the fit was much tighter. No charge, took all of 3 minutes. I will bring in all my jewelry repairs to J & M Jewelers now - nice, small town friendly and helpful service.