SRAM Red E1 2xOne piece 2x chainring results in a lighter weight, stiffer, more durable crankset X Range gearing technology gives you more range and a smoother gear progression, so youre always in the right gear Crisp and accurate front shifts Compatible with 8 bolt crank arms SRAM Model ID: CR RED KIT E1 Attributes BCD Direct Mount SRAM 8 Bolt Chainring Comp. SRAM FlatTop Speed 12