The Hellbender 110 Bottom Bracket provides an incredible mix of performance and longevity through the inclusion of Enduro XD-15 ceramic bearings. These bearings feature nitrogen infused stainless steel races that will not rust or corrode paired with Silicon Nitride ceramic balls. - Enduro XD-15 ceramic ball bearings are made from pure silicon nitride material with extreme high density and uniform compaction - The race material is an advanced stainless alloy that is nitrogen infused and will not rust or corrode - Dual stage anodize black and gold machined aluminum bottom bracket cups - Kluber NBU52 grease runs better and smoother with time and is highly resistant to being washed out - Designed for use with 30mm spindles