e*thirteen Helix R Direct Mount Chainrings, manufactured from durable AL-7075-T6, combine aesthetics and design efficiency. Their flip-flop design accommodates Boost or Super Boost chainlines. With e*thirteen's narrow-wide tooth profile, they ensure enhanced chain retention, reduced wear, and compatibility with Shimano and SRAM chains. Perfectly complementing all Helix Cranks, they're backward compatible with e*thirteen TRS, LG1, and XCX Race cranks.