Specification: 1. Material: zinc alloy 2. Type: Allen screws 2. Color: color zinc, adoptive color zinc finish prevents rusting 3. Size: M10 25, M8 20, M6 15, M6 10, M5 10, M4 10. 4. Quantity: 100 pieces in total Features of the insert nut: 1. These threaded inserts are inserted by screwing them into a pre-drilled hole, in which case the outer protrusions engage the wood and prevent the nut from rotating or pulling out. 2. Note: Before installation, first drill a sufficiently large hole with tools. If the material has a high hardness, please try to increase the hole size Warm hint: To facilitate installation, please drill a suitable hole before installation, please enlarge the hole if the material is harder. Package contents: 30 pieces x internal hexagon (M4 * 10) 30 pieces x internal hexagon (M5 * 10) 15 pieces x internal hexagon (M6 * 10 ) 15 pieces x internal hexagon (M6 * 15) 5 pieces x internal hexagon (M8 * 20) 5 pieces x internal hexagon (M10 * 25)