ADJUSTABLE STRUCTURE? The adjustable structure allows you to adjust your bicycle rear rack as needed. Assembled with screws, the seat plate can be adjusted by 3.15in/8cm in front and back. The support rod can be adjusted from 13.58in to 17.91in. Suitable for most bicycles, such as 26 "-29" mountain bikes. QUICK RELEASE: Both the main beam and the support rod feature a quick-release design, allowing installation without the need for holes. The bicycle's rear bracket forms a sturdy and stable triangular system, ensuring greater stability, pressure resistance, and preventing deformation and swaying. SOLID & STURDY:The bicycle cargo rack is crafted from high-quality, high-strength aluminum alloy, combining lightweight construction with robust durability. (Recommended Load: 55 lbs).The U-shaped bars effectively prevent pannier from hitting the tires, ensuring the security of your belongings. DESIGNED WITH FENDER?The mudguard can be installed in both the front and rear 4 hole positions, allowing for a 320° range of vertical adjustment. For added convenience, you have the option to install just the mudguards without the bike rear rack, providing you with versatile choices for your outings.