This top of the range headset is made from aircraft grade aluminium precision CNC cut alloy cups with quad sealed precision angular contact bearings coupled with double sealed bearing housing keeps the British climate at bay. Utilises flush seal technology to further protect the longevity of the bearings Full spares back up available Expanding collar design means once you tighten the headset it stays tightened Designed & tested in the UK for extreme British riding conditions Replacement R448B bearing available 40x 49x 6 45x 45