Material: Made of 7075 aluminum alloy, CNC machined with a narrow-wide tooth design to prevent chain drop and provide strong performance. Specifications: Compatible with 130mm BCD cranks. Easy to Use: Features mud discharge slots to prevent sediment buildup. Each tooth is precision CNC machined to smoothly engage with both inner and outer chain links, reducing friction and noise. Round Bike Chainring: Anodized finish helps prevent oxidation by forming a protective oxide layer on the aluminum surface, providing rust resistance and long-lasting durability. Note: This chainring is compatible with most 130 BCD cranks. Please verify your crank's BCD and required tooth count before purchase. Specification: Material: Aluminum alloy Size Chart: 50T: 20.9cm x 20.9cm / 8.23inch x 8.23inch 52T: 21.6cm x 21.6cm / 8.50inch x 8.50inch 54T: 22.5cm x 22.5cm / 8.86inch x 8.86inch 56T: 23.3cm x 23.3cm / 9.17inch x 9.17inch 58T: 24.1cm x 24.1cm / 9.49inch x 9.49inch 60T: 24.9cm x 24.9cm / 9.80inch x 9.80inch Package Includes: 1 x Bike Chainring Note: Slight measurement variations may occur due to manual measurement and display differences.