1、Aluminum alloy material guarantees light weight, T6 heat treatment guarantees the overall hardness, CNC knurling process guarantees the strength. 2、The expansion pawl, upper and lower stop are made of aluminum alloy, and the pull rod is made of stainless steel to increase the strength. 3、This waterproof and dustproof protective expansion hanging core has a variety of stem cover options, which are stylish and beautiful. 4、The installation closely fits the front fork without gaps, and this bicycle headset expender plug can be repeatedly disassembled and used repeatedly. 5、Suitable for front forks with an outer diameter of 28.6mm at the upper end, carbon fiber forks for road bikes and suspension forks for mountain bikes. Item Type: Bicycle Fork Headset Material: Aluminum Alloy Size: Length: Approx. 38mm / 1.50in(Without Threaded End), Upper Width: Approx. 28.4mm / 1.12in, Bottom Width: Approx. 19.3mm / 0.76in Suitable for Front Forks: The Outer Diameter of the Upper End is Approx. 28.6mm / 1.13in(Both Carbon Fiber Front Forks and Mountain Suspension Forks) 1 x Bicycle Fork Headset 1 x Stem Cover 1 x Screw