Review on Waterproof Bike Seat Bag by ROCKBROS, 3D Shell Saddle Bag for Mountain and Road Bikes - Cycling Seat Pack Under Seat by Franklin Richardson

Bought 2 of these in September 2019 for $18.99 each. Installed on 2 different bikes. One could not endure two short journeys on the towpath. The other traveled about 85 miles on the trail. The tow trail is smooth trail for the most part and none of these bags were loaded with anything loadable. The elastic strap that attaches the bag to the seat post ripped on both bags. I suggest you look for something more permanent. There were no problems with the bag itself, but now both are unusable.