Features: This spacer is made of quality aluminium alloy material, high strength, anti-rust, wearable, non-deformation, durable. It can make 1-1/2in bike tube compatible with 1-1/8in front fork, suitable for 55mm & 56mm below headset. Inner diameter is 30mm, outer diameter is 45mm. Easy to install. Useful accessory for bike lovers to DIY their bikes. Specification: Material: Aluminium alloy Color: Shown as picture Outer Diameter: Approx. 51mm / 2in Inner Diameter: Approx. 30mm / 1.18in Thickness: Approx. 4.5mm / 0.177in Weight: Approx. 13g Package List: 1 x Spacer .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; } 1This spacer is made of quality aluminium alloy material, high strength, anti-rust, wearable, non-deformation, durable 2It can make 1-1/2in bike tube compatible with 1-1/8in front fork, suitable for 55mm & 56mm below headset 3Inner diameter is 30mm, outer diameter is 45mm 4Easy to install 5Useful accessory for bike lovers to DIY their bikes