EXPANDABLE - The Bicycle Rear Rack Bag is the perfect travel companion for your bike. With an expandable top section so that you can comfortably carry everything you need with out hindering the ride INTEGRAL COVER - The Tekbox Bicycle Rear Rack Bag comes with a rain cover so that you can be worry free even if the weather changes SPACIOUS - This bike bag is expandable so you can comfortably fit everything you need into it easily. This means you do not have to worry about feeling restricted or risk cycling with extra bags or backpacks, reducing risk on the road and increasing your safety. REFLECTIVE - Reflective straps ensure that you can be seen when you are cycling at night PLEASE NOTE - This Bicycle Saddle Bag requires an existing rear bicycle rack to attach it to