BSA, 4-edge, JIS / ISO, Ø 68 mm housing. Excellent corrosion protection thanks to the high quality A2B-DeltaColl® galvanization. Ideal seat in the bottom bracket shell thanks to a special left adapter with shoulder functions (FS-Cup). Ball bearings: 2RS (both sides sealed). PA6.6 30% GF Durethan® adapter. Including A2A-10.9 galvanized screws with polyamide coating. Durable ball bearings: DIN-ISO281: 1993 min. 35,000km.