Specification BikeType : Mountain Bike Brand : X AUTOHAUX BulletPoint1 : Size: 25.4mm to 27.2mm, 25.4mm to 28.6mm, 25.4mm to 31.6mm. Inner Diameter 1: 25.4mm / 1", Outer Diameter 1: 27.2mm / 1.07", Inner Diameter 2: 25.4mm / 1", Outer Diameter 2: 28.6mm / 1.13", Inner Diameter 3: 25.4mm / 1", Outer Diameter 3: 31.6mm / 1.24" BulletPoint2 : Material: Made of aluminum alloy, anti slip, anti rust, durable in use. Color: Black BulletPoint3 : Installation: Easy to install and remove, no drilling or cutting required, no tools are needed, just a few seconds to install directly to the bicycle. BulletPoint4 : Application: This product is suited for most bicycles such as MTB bikes, mountain bikes, road bikes, etc. BulletPoint5 : Please check the outer diameter of your bicycle seat tube before placing the order. Measure the inner diameter of the old clamp or the outside diameter of the seat tube. Then make the right choice. GpsrSafetyAttestation : 1 ItemName : X AUTOHAUX 3 Pcs 25.4mm to 27.2mm 25.4mm to 28.6mm 25.4mm to 31.6mm Bicycle Bike Seat Post Tube Adapter Seatpost Reducing Sleeve Adapter Aluminium Alloy Black ItemPackageDimensions_Height : 1.38 inches ItemPackageDimensions_Length : 5.51 inches ItemPackageDimensions_Width : 3.94 inches ItemPackageQuantity : 3 ItemTypeKeyword : bike-seat-posts-and-parts Manufacturer : X AUTOHAUX Material : Aluminum PartNumber : a23052700ux0346 ProductDescription : Feature: Bicycle Seat Post Adapter is made of aluminum alloy material, which is durable in use. Stylish appearance, portable, not rust easily, transforms your vehicle's plain interior and adds a unique of color. Easy to install and remove, no drilling or cutting required, just install directly to the bicycle.