Outtag Retractable Aluminum Alloy Bike Mount Cycle Bicycle Rear Seat Post Rack (Cling-on Easy Install,max Weight 22lb) Made of high quality hard Aluminum Alloy,durable and sturdy Easy to install,quick-release bag mounting system Supports up to 22lb of cargo Dimension:approx 34cm x 12 cm(L x W) Package content: 1 x Aluminum Alloy Bike Mount Cycle Bicycle Rear Seat Post Rack,1 x Allen key4 x pads for protecting the seatpost from the bike rack. As different bicycles of seat post is not the same size and installation angle, please <span class="a-text-bold">use the pads</span> when you install it. And please <span class="a-text-bold">install firmly</span> without any loose and then load your package. Due to the loading of the cargo, put in different position of the scaffold, leading to stress points. Due to the different pressure, so it is best not to over or close to the <span class="a-text-bold">Maximum Load Weight 22lb</span>. During installation of goods or package, please <span class="a-text-bold">do it gently</span> to avoid uneven force causing goods fall or bike fell down.