a few days after i received this bag .there was a down pour of rain in balto. area 3" in 1 hr. so I thought I would put the bag to waterproof test. set bag out in driveway for duration of storm about 1 1/2 hrs. at the end of storm inside of bag was completely DRY. well worth the money Ortlieb was great products also have 3L seat bag that I used for ride across America it to was put to the test and PASSED each time.