The Kokopelli Durango Seat Post Bag locks onto the seat post with a FidLock(R) quick-connect base, so taking it on and off never turns into a fumble with straps. A roll-top TPU shell seals out water and weather completely, keeping everything inside dry no matter the forecast. Removable PE boards add structure when the bag's loaded down and pull out for a softer pack when it isn't, and upper and lower compression straps keep the whole thing cinched tight and quiet on rough ground. What Our Gearhead(R) Experts Are Saying:"I hit washboard gravel for miles and the bag never budged or rattled once it was locked onto the FidLock base."