CHP Tweezers may have variations in the measurement of the opening between the tweezer points. There is no set standard for this, so it is possible that you may have two tweezers of the same part number but the opening at the end of the tweezers will measure differently. Typically, the opening will measure around 7mm to 10mm. If you need to increase the opening, not that the two pieces are welded together so it is possible to expand the opening a few millimeters without damaging the weld point.