Product Description Spare aluminium crown race for the 110 series by Cane Creek. Models:IS41/30 Compatibility: integrated (IS), external cup (EC), zero stack (ZS)Head Tube (Frame Inner Diameter): 41 mmCrown Steerer Tube: 30 mmAxle to Crown: 1 mmUse: 1 1/8" lower head tubes in combination with standard 1 1/8" lower steerer tubesManufacturer Number: BAA0170A IS47/33 Compatibility: integrated (IS), external cup (EC), zero stack (ZS)Head Tube (Frame Inner Diameter): 47 mmCrown Steerer Tube: 33 mmAxle to Crown: 1 mmUse: 1 1/4" lower head tubes in combination with standard 1 1/4" lower steerer tubesManufacturer Number: BAA0699A IS52/30 Compatibility: integrated (IS), external cup (EC), zero stack (ZS)Head Tube (Frame Inner Diameter): 44 mm, 49 mm, 52 mm, 56 mmCrown Steerer Tube: 30 mmAxle to Crown: 1 mmUse: For 1.5" lower head tube diameters combined with standard 1 1/8" lower steerer tubes. Manufacturer Number: BAA0463A IS52/40 Compatibility: integrated (IS), external cup (EC), zero stack (ZS)Head Tube (Frame Inner Diameter): 44 mm, 49 mm, 52 mm, 56 mmCrown Steerer Tube: 40 mmAxle to Crown: 1 mmUse: For 1.5" lower head tube diameters combined with 1.5" forks. Manufacturer Number: BAA0173AStandardized Headset Identification System (S.H.I.S.):In order to clarify and bring uniformity to a sea of headset standards, manufacturers Acros, Cane Creek, Hope, Race Face, Reset Racing and Ritchey have agreed upon using a shared nomenclature, which will likely include more participating companies in the future. This system takes into account a combination of frame and fork dimensions. Both the upper and lower part of the headset are marked by two alphanumeric identifiers. The first identifier indicates the type of headset (External Cup, Zero Stack, Integrated) and head tube diameter. The second identifier - separated from the first by a backslash - indicates the diameter of the steerer tube. When referring to a complete headset, the specifications of both upper and lower parts must be combined. Nomenclature:EC:Bearings contained within cups that are located outside of the frame (external cup).ZS:Bearings contained within pressed-in cups where the cup and bearings rest inside the frame (zero stack).IS:Bearings that fit directly into a bonded or machined interface that is integrated into the frame (integrated).Contents:1 x Cane Creek 110 crown race Manufacturer: Cane Creek Cycling Components 355 Cane Creek Rd Fletcher NC 28732 USA info@canecreek.com Distributor: Cosmic Sports GmbH Leyher Straße 47 90763 Fürth Germany info@cosmicsports.de