The bag is a heavy duty S2S dry bag
https://www.rei.com/product/786435/s...-bag-20-liters
Two S2S compression bags inside the dry bag
Attached with a Revelate harness
https://www.revelatedesigns.com/inde...ndlebarharness
and a Revelate small bag clipped to the front
https://www.revelatedesigns.com/inde...le-bar/Pockets
Very secure setup, with no movement and no shimmy. Hit 47 mph outside Carmel, CA and the bike felt great.