The drag chain is shaped like a tank chain and consists of numerous unit links that rotate freely between them. The inner height, outer height, and pitch of drag chains of the same series are the same. There are different options for the inner width, and bending radius R of drag chains. The unit chain link consists of a left and right chain plate and an upper and lower cover plate. Each link of the drag chain can be opened, making it easy to install and disassemble without threading. After opening the cover plate, cables, oil pipes, gas pipes, water pipes, etc. can be placed into the drag chain.