- They are made of special spring tempered stainless steel that can withstand hundreds of cycles without deform. - This material has ideal spring action for Rubber Dam Clamps, as well as maximum corrosion resistance. - Every production lot is examined by metal fatigue test which assures good spring action and long life time. - Matt ad Black clamps provide very less light reflection protecting the eyes especially when working with microscopes. **For further product information, please contact Chat Support**