https://www.fieldsupply.com/slumberjack-reign-15l-sling-pack-leaf-green.html
These are single-strap sling bags, not full backpacks. I think they’re a good size for vehicle “go-bags” though.
Field Supply is slow shipping, but have bought from them before with no issues other than shipping speed.
I purchased 3:
More info:
Durable polyester oxford
Padded air-mesh back panel & shoulder strap
Zippered front pocket with organization
Small zippered stash pocket
Padded grab handle
PALS attachment points
Embroidered hook/loop morale patch
Custom logo treatment
- Volume: 915 cubic inches/15 liters
- Weight: 1 lb. 5 oz.
- Dimensions: 17"H x 10"W x 6"D
- Fabric: 600D Polyester