uxcell Round Head Knurled Thumb Screw M2.5x5mm Hand Clamp Screw Screws Knob Bolt for Vernier Caliper 4 Pcs Brand new. Size - M2.5x5mm thread size, 5.5mm head thickness, 7mm head diameter Material - Made of stainless steel, which has excellent corrosion resistance, high temperature strength, scaling resistance, and low temperature toughness. Features - The knurled surface of these thumb screws provides optimal grip, allowing you to tighten or loosen the screws with hand pressure alone, without the need for tools. Knurled screws are common in applications where frequent tightening and loosening is required. Application - Suitable for vernier calipers. Package Contents - 4 x Flat Head Knurled Screws 35-16/859/@