Surely, our product can be used for a long time because it has good wear resistance and corrosion resistance, and it also has a compact structure at the same time. No doubt, the screws are made of 304 stainless steel, which it has good anti-rust performance. And the thickness of the head is only 3mm, which it can protect the fork from being scratched. It is made from aluminum alloy and stainless steel, is durable to use. There are two sizes of the product to choose from. Front hub 15mm, barrel shaft 100mm, suitable for open gear conversion 110mm open gear; rear hub 12mm, barrel shaft 142mm, suitable for open gear conversion 148mm open gear. Item Name: Boost Hub Adapter Material: Stainless Steel,Aluminum Alloy Features: Ultra-light, Anti-rust, High Hardness Color: Black Specification: Front Boost Hub Adapter, Rear Boost Hub Adapter Size Details: A Thickness: 0.5cm/0.2" (Approx.) B Thickness: 0.3cm/0.12" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Boost Hub Adapter 2 x Washers 6 x Screws