1. Material: aluminum alloy 2. Triangle type fixing method, good safety and weight bearing 3. Waterproof surface, not easy to rust and anti-scratch 4. Quick release mounting, non-slip and stable, not easy to scratch the seat tube 5. Anti-vibration screws, effectively prevent the shelf from loosening 6. The bracket can be retracted, strong applicability 7. Warning light on the rear rack, safer to ride 8. Size: shelf length about 55cm; panel length about 40.5cm