304 Stainless Steel: These quick links are made of 314 stainless steel, which has higher hardness and resistance than other common alloy steel materials. High-quality hardware can withstand bad weather for a long time and is extremely and safe. Easy to use: Turn the thread clockwise to open and counterclockwise to close. And the extremely smooth thread, it is very convenient to install and remove even if it is closed for a long time. Easy to use: The installation of the chain connector does not require any tools; turn the thread clockwise to open and counterclockwise to close, which is very easy to install and remove even if it is closed for a long time; the working load limit is 648 pounds. Hexagonal thread locking: The locking chain has a special threaded end and barrel screw, which is reliable and convenient; the threaded connection can be tightened or loosened without tools, but its hexagonal design allows for additional tightening with a wrench. Wide Application: Heavy-duty chain link hardware is widely used as chain link connectors and chain accessories, such as extending porch swings, raising hanging lights, extending trailer safety chains, camping, hiking and other activities. Colour:Silver Material:Stainless steel Package Contents: 30 * 4MM Quick Connect Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.