This clamp knob is made of high quality plastic and iron, with good toughness and impact resistance, strong and durable. Widely used in related industries such as mechanical equipment, electronic equipment, communication equipment, hardware lighting, building bridges, etc. It can also be installed at the bottom of furniture to improve stability and prevent scratches and noise. Easy to use, just align the hand-tightening knob with the hole of the corresponding thread and screw it in, no other tools are needed to tighten it. The button head groove design is ergonomic, making it easy to tighten by hand. Hardware : plastic iron Thread size: M6 x 20mm Size: M6 x 20mm Features: This button clamp is made of high quality plastic and iron, with good toughness and impact resistance, strong and durable. Widely used in related industries such as mechanical equipment, electronic equipment, mechanical equipment communications, equipment lighting, construction bridges, etc. It can also be installed at the bottom of furniture to improve stability and prevent scratches and noise. Easy to use, just align the hand-tightening knob with the hole of the corresponding thread and screw it in, no other tools are needed to tighten it. The button head groove design is ergonomic, making it easy to tighten by hand. Features: Material: Plastic Iron Color: Black. Thread Size: M6 x 20mm Contents: 2 triangle head clamping knobs. Notes: 1. Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Because the measurement is taken by hand, the sizes shown may vary from 1 to 3 mm. We thank you for your understanding.