The item under consideration is referred to as a hybrid conveyor belt. It is described as a custom-made steel and plastic hybrid conveyor belt designed and used exclusively with conveyor systems. The belt is fixed to the drive elements of a conveyor, which allows it to circulate and transport products to an end point or discharge point. It will consist of a steel base roller chain with polyethylene top plates, on which items will sit during conveyance. Each polyethylene top plate is molded with two holes on each side that clip onto extended pins within the base chain. The units may also include optional grippers, which are accessories designed to hold fragile goods in place during conveyance to provide stability and prevent shifting during transit. You state the grippers are fully attached to the top plates at time of importation. The hybrid conveyor belts are imported fully assembled and ready for use. They are available in a variety of sizes and pitches.
[1] Please importantly note that only the relevant portion of the related is displayed above. You may refer to the said customs ruling for the entire ruling explanation.
[1]. https://rulings.cbp.gov/ruling/N320854