Material: Made of 7075 aluminum alloy, CNC machined with positive and negative tooth design to help prevent chain drop and improve power transfer. Specifications: Compatible with 130mm BCD cranks. Easy to Use: Features mud discharge grooves to reduce sediment buildup. Each tooth is precision CNC machined to smoothly engage with both inner and outer chain links, reducing friction and noise during operation. Round Bike Chainring: Anodized finish helps prevent oxidation and corrosion, forming a protective layer on the aluminum surface for increased durability. Note: This chainring is designed to fit 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 variations may occur due to manual measurement and differences in display monitors.