1. Vernier caliper fastening screws is to use the fastening screws on the vernier to fix the vernier in any position.2. Made of stainless steel for wear-resistant and anti-corrosion.3. Round thumb screw with flat knurled head style.4. Knurled head provides extra grip for manual tightening.5. Suitable for vernier calipers6. Notice: Please confirm the vernier caliper fastening bolt size before buying.