Revelate Design Viscacha Seat Bag: Black Updated version includes: new saddle attachments that allow for better adjustments with different saddle positions, and new side compression hardware that makes it easier to tighten down while riding NOTE: Design Change - Instead of having 2 seatpost straps, it now has a Single Seatpost, Anti-slip strap Roll down opening allows the bag to easily expand or compress in volume Dimension Polyant 200 Denier Fabric Plastic HD bottom sheet, high density foam inserts