BLACKBURN OUTPOST ELITE SEAT PACK We developed our Outpost Elite Universal Seat Pack (USP) to work with dropper or standard seatposts, be able to carry a bevy of cargo, and be stable enough to not swing around while it does. The USP is a two-part system: Part 1 is a T6061 Alloy Wing that affixes to your saddle and works with a standard or dropper post. Part 2 is a removable and waterproof dry bag. The bag has a scuba-style air bleed valve to assist with compression while off the bike. The wing stays on the bike, the bag comes off and allows you to pack, compress and go ride in the snap of a few buckles. Features: - Bag Capacity: 5,25L/6,95L (Expanded) - Water Resistance: Water resistant, extra protection against the elements. - Dropper Compatible: Designed to not only stabilize your seatpack, but also work with or without dropper posts. The T6061 aluminum wing bolts to your seat rails for a rock solid mount. Get the perfect cargo fit for the roughest trails. - Harness System: The bag features a system that is comprised of an outer "Harness" that securly carries an inner bag. The inner bag can quickly and easily be removed form the harness, without having to detach the harness from the bike. The advantage is that it saves time, is more secure and allows you to carry odd/oversized items or use your favorite aftermarket bags. - Bleed Valve: The waterproof dry bag features a scuba style air bleed vlave so that you can pack your bag as tight as you need, and not have to worry about leaks. - Welded Seam Construction: Welded seams not only reduce bulk and materials, they improve performance by eliminating the needle hole, a potential area for saturation and leakage. Welded seams also create a clean finish on both the interior and exterior of the bag. - No sway: Able to carry a bevy of cargo, and stable enough to not swing around while it does.