Product Description Chromag is the only MTB company officially authorised to manufacture chainrings with SRAM's X-Sync™ technology. Technical Information:Material:aluminium (7075-T6)Teeth:30, 32, 34, 36Bolt Circle Diameter:104 mmMount:Standard (4-arm)Compatibility:ShimanoSRAMRace Facecranks from other manufacturers of the model years 2000-2014Features:official SRAM X-Sync™ technology, meets SRAM compatibility requirementssensationally secure chain retentionbest possible self-cleaning of mud and dirtCNC machinedblack anodised, laseredmade in CanadaTechnologyX-Sync™ X-Sync™ chainrings ensure maximum performance and durability. The long SRAM X-Sync™ tooth edges grip the chain earlier than standard triangular teeth. The sharp and narrow tooth profile and the rounded bevelled edges support the chain guide. To guarantee the best possible performance for muddy terrain, X-Sync™ chainrings have recesses for the inner chain links and rollers to remove dirt and mud. Manufacturer Numbers:30 tooth:151-001-00132 tooth:151-001-00234 tooth:151-001-00336 tooth:151-001-004Contents:1 x Chromag Sequence chainring Manufacturer: Chromag Bikes 1121 Industrial Way Squamish BC V8B 0H1 Canada info@chromagbikes.com Distributor: bc GmbH Carlo-Schmid-Straße 12 52146 Würselen Germany info@bike-components.de