If you are into backpacks this one has likely crossed your search results, as it is a fantastic design : ) This is nearly a 50% discount to purchasing new and I collected nearly every accessory that makes this pack so versatile! (Their site does a great job of explaining the modularity and features: https://www.boundarysupply.com/products/errant-pack?variant=12184799576100 All items (and price new) - Errant Pack: $239 - Aux Compartment: $74 - CB-1 Camera Insert: $64 - Mk-2 Camera Cube: $69 - EXM Port 6 Liter: $65 - Thermal Insert: $49 - Tech organizer: $42 - Magnetic Chest strap: $21 - Sr2 Lash Straps: $19 - HT Key Clip: $19 - External ‘X’ strap: $19 Total: $680 Small sample of how I used this bag / what is awesome: - Bottom waterproof compartment for shoes or cooler - hidden passport pocket for travel and cash - 5 performance mesh pockets for chargers, snacks and water bottle - External lashing points for blankets, tripods, yoga mats, gimbal - Expands from 22 Liters to 30 Liters with included accessories - amazing hidden sunglasses pocket Example of how accessories can be used: - Thermal insert cooler fits perfectly in the waterproof bottom compartment - Tech organizer suspends internally from inner clips - Aux compartment attaches externally - 6 Liter mini duffel bag attached externally to bottom of bag - Keys clip attaches to internal small side pocket - Shoulder strap attached to both CB-1 Camera insert and MK-2 camera cube to use as standalone carry.