So I got the Fjällräven/specialized saddle bag carrier thing for a great deal,(45€) but I found it swings a lot form side to side. I installed all the parts that came with
Specialized/Fjällräven Handlebar Rolltop Bag – Rock N' Road
S/F Expandable Hip Pack
S/F Seatbag Drybag 16L
Specialized + Fjallraven Drop 3 | Bike, Fjallraven, Handlebar bag
We Tested Fjällräven & Specialized's new Bikepacking Gear - YouTube
Collection from Fjällräven/Specialized
S/F Seatbag Drybag 16L
S/F Seatbag Harness
Bike Bags for Travel and Nature Exploration | Fjällräven