This particular design of chain has a hollow bearing pin allowing for the installation of various attachments. Usually, these chains are used for conveyors. The advantages of installing attachments into the hollow pin include the following:

• The hollow pin is at the centre of articulation, and always keeps the pitch length. Regardless of whether the chain is straight or wrapping around the sprocket, the centre distance of attachments is always the same. 

• With a cross rod over two chains, the load from the attachments is distributed equally between the link plates. The chain can fully utilise its strength and will not twist.

• Easy to change, maintain, and adjustment.

• Standard sprockets are used for the single pitch series. For double pitch series, standard sprockets for double pitch roller chain are used