Description: Front Hub Adapter: The front 15mm boost hub adpater allows 100mmx15mm front hub convert into 110mmx15mm. Rear Hub Adapter: The rear 12mm boost hub adpater allows 142mmx12mm front hub convert into 148mmx12mm. Material: Made of aluminium alloy material, which is high strength, anti rust, non deformation and durable. Package Includes: This set includes 1pcs hub conversion adapter, 2pcs spacer and 6pcs bolts. Easy to Use: Comes with necessary accessories, easy to install and convenient to use. Specification: Item Type: Bicycle Hub Conversion Adapter Material: Aluminium Alloy Size Chart: Hub Conversion Adapter Size: 3mm: About 44x3mm/1.73x0.12inch 5mm: About 44x5mm/1.73x0.2inch Spacer Size(Outer Dia. x H): 3mm: About 18.9x3mm/0.74x0.12inch 5mm: About 21x5mm/0.83x0.2inch Bolts Size(Dia. x H): About 9.9x17.4mm/0.39x0.69inch Package Includes: 1 Piece Bicycle Hub Conversion Adapter 2 Pieces Spacer 6 Pieces Bolts(3 Pack) Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping!