![DT Swiss Threaded Ring Tool for DT Swiss Ratchet System Hubs DT Swiss Threaded Ring Tool for DT Swiss Ratchet System Hubs](https://cdn11.bigcommerce.com/s-tpvx4esvgk/images/stencil/500x500/products/156555/408791/50910__92785.1706688641.jpg?c=1)
This O-ring is suited for DT Swiss rear hubs and have to be mounted between hub body and freehub. It protects against water and dirt.
Compatibility
DT Swiss hub 180
DT Swiss hub 190
DT Swiss hub 240
DT Swiss hub 240s
DT Swiss hub 340
DT Swiss hub 350
DT Swiss hub 440
DT Swiss hub 540