Easy to install Bicycle Saddle Bag under seat post with reflective design and multiple pockets for different usages. able to install lights on the bag too. Product detail: Name: ROCKBROS saddle bag Brand: ROCKBROS Size: About8.4*16.5*9.6*12.8mcm Weight: About 120G Fit for: Folding/MT Bike Feature: Bag with the waterproof zipper Reflective and light hook More secure in night Patented exterior design More fitting to bike Portable, Shockproof Do note that the material is NOT fully waterproof, it cannot withstand heavy rain / submerged water