Machined from 6061T6. Stainless fasteners with Neoprene gripper ring. Clamps are modified Cateye brand name clamps, the top within the small business for toughness and variety of sizes. We propose the flagpole be mounted close to the back with the seat and in a slight rearward angle (not really vertical). https://petera150xnh8.wikistatement.com/user