Features a 360 degree adjustable view, allowing easy angles for full rear visibility and enhanced riding . High strength carbon steel frame, with high hardness, not easy to break, safe and enduring. Suitable for mountain bikes, road bikes, and folding bikes with handlebars diameter of 21.8mm/0.86inch. Provide dependable , maintaining long lasting stability even when facing shocks or bumps. The cycling looking glasses provides easily setup without relying for complex tool, ensuring fast assembly.