A. This stem expander for the front fork steerer tube of mountain bikes and road bikes comes with screws and a stem cap. It is made of aluminum alloy. Aluminum alloy has many advantages. It is relatively light in weight, which can effectively reduce the overall weight of the bicycle and improve the handling flexibility and speed during cycling. In addition, it also has good strength and durability, being able to withstand various impacts and pressures during the cycling process and providing reliable support for cycling. B. This stem expander for the front fork steerer tube is precisely manufactured to specific specifications. Its model is S11TC, and it is suitable for mountain bikes and road bikes. The precise fit allows it to combine well with the bicycle, and the installation process is simple. Whether you are riding smoothly on flat roads or challenging yourself on rough mountains, it can function stably and contribute to your cycling journey.