1. The measurement of screw posts: The screw bolt consists of a screw and a . The screw size is 4 x 4 mm, while the size is M5 x 5.5 mm. They are matched, and the total length is 6 mm.<br> 2. The hard material: This set of male and female screws is made of steel, hard, sturdy, and durable. The surface is plated with nickel, making it resistant to rust and corrosion.<br> 3. The useful vice: This set of screw bolts is easy to install. Simply drill a 5 mm diameter hole, then assemble the two parts from both sides. They can secure various items.<br> 4. The quantity: This package includes 50 screws and 50 tops, providing ample supply for your needs.<br> Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin