What is a truck? It is the top part of the flagpole commonly known as the pulley. All flagpoles have specific trucks or pulleys that are better for their use. Smaller flagpoles or sectional flagpoles often use the eyebolt and pulley system or a side mount pulley for the halyard (rope). Larger flagpoles use a truck unit that houses the pulley within its cast aluminum frame. This Side Mount Pulley unit is made of cast aluminum with a cast nylon pulley on a 1/4″ stainless steel axle. The unit can be attached with either two 1/4″ screws or stainless steel straps (neither included). The largest halyard (rope) size should be 5/16″. Guide marks are dimpled in the casting as sets to drill holes for setting.