Tortec: The Explorer rack has been designed with a quick release clamp so it can easily be mounted to seat posts between 25.4mm and 31.8mm. The top plate encompasses a luggage strap making it ideal for commuting and trail use. Rear mounting plate supports upto 3 rear lights/reflectors.DimensionsA: 120mmB: 115mmC: 215mmD: 505mmE: 350mmF: N/AMax Tyre Width: 100mmRack Tube Thickness: 8mmSeatpost Width: 25.4 - 31.8mmMax Weight: 10kg5 Year Warranty