Cane Creek AER II Series Headset Bearing - Blue - Steel-Aluminium - 1 1-8 Inch - 30.15x41x6.5mm - 36x45 - IS41 PDP|Colour Here is the break down:

Here is the break down:

Manufactured in the US of A out of top quality 7075-T6 Alloy and Type II anodised

10s Cassette Compatibility:

The TK-4 was painstakingly designed with pockets and holders for specific tool shapes and sizes as well as some generic storage areas

Cane Creek AER II Series Headset Bearing - Blue - Steel-Aluminium - 1 1-8 Inch - 30.15x41x6.5mm - 36x45 - IS41 PDP|Colour Here is the break down:Genuine Cane Creek AER II Bearing. Made from Steel and Aluminium for the lightest possible bearing. Even though it manages to shave a whopping 35% off the weight of a standard bearing, it still maintains the quality and durability that Cane Creek bearings have become known for. The best part is, these are cross compatible between all of Cane Creek's other headsets! So you can upgrade your Ten, Forty or 110 series headset to have AER II bearings.