Crafted of aircraft-grade aluminum, U-Tubes support your passengers' feet and offer cargo support. They have great weather resistance, letting them shrug off the effects of sun, rain, and muddy boots. For cargo, they work great for supporting cargo like bags of groceries, bricks, buckets of paint, you name it. They also make bike towing a breeze. U-Tubes can be adjusted to a wide and narrow setting. They are sold in pairs and attach with a bolt that goes through a boss on the bike or kit frame.