High Quality Material: Made of AL7075-T6 aluminum, CNC machined and anodized for a smooth surface, bright color, fade resistance, and corrosion resistance. Elliptical Design: Eliminates trampling dead spots, increases leverage distance for optimal starting power, prevents chain skipping, improves efficiency, enhances speed, and operates smoothly with minimal noise. Knee Protection: The chainring design helps distribute pedaling force more evenly, providing better protection for the knee meniscus and reducing knee strain during climbing and long-distance rides. Compatibility: Designed for 14/16/20-inch folding bicycles. 45T and 47T are suitable for 14-inch bikes. For 16-inch folding bikes, use a chainring under 53T. For 20-inch folding bikes, use a chainring under 56T. Specifications: - Material: AL7075-T6 aluminum - Speed: 45T, 47T, 53T, 56T, 58T - Color: Red, Gold, Silver, Black - BCD: 130mm - Diameter: 45T - 192mm; 47T - 200mm; 53T - 224mm; 56T - 235mm; 58T - 245mm Package Includes: 1 x Bike Chainring Note: Chain length may need to be extended when installing a larger chainring. When selecting a larger chainring, ensure the diameter is within an appropriate range to avoid clearance issues; in some cases, a longer axle may be required.