Product Description The e*thirteen lock screw for second-generation TRS, XCX and Helix cassettesThis screw from e*thirteen with 3 mm length serves as a spare part for second-generation TRS, XCX and Helix cassettes. It serves as a fuse for the two sprocket clusters. Compatibility: TRS Gen2 cassette DBA e*thirteen 1445 Technology Lane STE A9 Petaluma CA 94954 USA support@ethirteen.com Distributor: Cosmic Sports GmbH Leyher Straße 47 90763 Fürth Germany info@cosmicsports.de