Clear Visibility: RBRL bicycle rearview mirror features high-quality automotive-grade convex glass with a 3-layer design: scratch-resistant, high-definition, and shatter-proof. Enjoy an ultra-clear, wide rear view and eliminate blind spots Robust and Durable: Mirror arms are made of reinforced nylon fiber for superior impact resistance, while the aluminum alloy base provides stability and corrosion resistance. Stays firmly in place even on rough terrain 3-Screw Secure Locking System: Three screws on the back of the rear view mirror enhance its secure fit, preventing wobbling or loosening during riding and maintaining your desired viewing angle. Follow the included installation guide or video to lock the mirror securely in place Break-proof Innovative Structure: The RBRL bike mirror’s 360° auto-rotating pivot arm rotates automatically on impact, preventing breakage and keeping the mirror securely attached. This smart design ensures long-lasting durability, so the mirror stays safe even on rough roads or during accidental tip-overs. Compact design allows easy storage or leaning against walls when not in use Universal Compatibility: Suitable for most standard flat handlebars with diameters from 22.2mm to 25.4mm, compatible with e-bikes, mountain bikes, cruisers, scooters, and city bikes. Please watch the installation guide for proper setup