Product Description The ZS44/28.6 headset top assembly from Acros, with a semi-integrated design for 1 1/8" head tubes and standard or tapered steerer tubes, is an all-round worry-free product. It impresses with double sealed angular contact ball bearings made of stainless steel, optimised headset grease and additional seals. Use:Designed for 1 1/8" upper head tube diameters combined with standard 1 1/8" or 1 1/8" - 1.5" tapered forks.Specifications:Application:Road, Gravel, All Mountain, Cross Country, Enduro, City & TouringDesign:Zero Stack (ZS)Top Outer Diameter:44 mmTop Inner Diameter:28.6 mmHead Tube:1 1/8"Steerer Tube:1 1/8" , 1 1/8" - 1.5" taperedTechnical Information:Material:aluminiumBearings:Stainless steel angular contact ball bearings, double sealedUpper Insert Depth:7.7 mmTop Stack Height:8 mmSeals:dual double lip sealFeatures:optimised headset greasedual double lip seal offers protection from moisture and dirtcompression ring made of fibreglass-reinforced composite material with vulcanized seallong durability with minimal maintenanceStandardized 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 top and bottom parts 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 top and bottom parts must be combined. Nomenclature:EC:Bearings contained within headset cups that are located outside of the frame (External Cup)ZS:Bearings contained within pressed-in headset 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)Manufacturer Numbers:black:22.02.605R6Sred:22.04.605R6Sblue:22.05.605R6SContents:, consisting of: 1 x headset cup with stainless steel bearings1 x top cap1 x Ahead cap1 x star nut with aluminium bolt1 x compression ring Weight: black | ZS44/28,6: 43 g Manufacturer: acros sport GmbH Benzstraße 58 71272 Renningen Germany info@acros-components.com