Thread Size:M4 x 0.7mm;Hex Width :7mm/0.27inch;Dome Head Size:7x4mm(Max.D*Height);Height : 8.0mm/0.31inch Material: Brass, corrosion resistant galvanized finish to ensure life-time use. Widely used in machinery, plumbing, electrical,furniture and fencing projects ,They are used to cover exposed bolt threads. Acorn Nuts help prevent stripping of the threads and a provide a decorative appearance as a finishing fastener,protects against exposed screw threads. Package Content: 20Pcs x Cap Nuts Note: It does not include other things, the color is based on the first picture, and the other pictures only show the effect Due to the differences between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement. Please allow deviation. Thanks!