When sourcing a small box trailer, you must prioritize the Gross Vehicle Weight Rating (GVWR) and Payload Capacity to ensure it meets your hauling needs. Look for frames made of hot-dipped galvanized steel to prevent rust, especially for coastal or humid regions. The suspension system is critical; leaf springs are common for heavy loads, while rubber torsion axles provide a smoother ride for fragile cargo. Additionally, verify the flooring material, such as checkered aluminum plate or marine-grade plywood, for durability and slip resistance.