This backpack packs down into a tiny stuff sack, making it easy to keep on the bike “just in case.” Very handy for when you realize you need to stop by the grocery store on the way home, or happen by a cool yard sale. Has side pockets that can fit a Nalgene, and bungee cord on the back that can clamp down extra layers and whatnot.

Here’s the breakdown from Peregrine:

The Peregrine Azor 20 is an ultralight roll top dry-pack for those trips within trips. With fully seam-sealed nylon 6,6 CORDURA® fabric, this pack excels in rugged, wet climates. The shoulder harness is lightly padded with durable air mesh and features a built-in carry handle. Two generous stretch-mesh side pockets easily accommodate 32oz Nalgene bottles. A dual-use cordage system allows for quick storage of outer layers and instant pack compression if your pack contents are low volume. When space is scarce, pack it down to the size of a baseball in its included stuff sack.

• Weight: 4.3 oz (122 g)

• Volume: 1220 in³ (20 L)

• Dimensions: 9.4 x 8.3 x 23.3 in (24 x 21 x 59 cm)

• Fabric: 30D Sil/PU RS Nylon 6,6 CORDURA®

• Available colors: grey and blue/yellow

• Lightweight air mesh shoulder straps

• Cordage compression system

• Fully seam-taped construction

• Two stretch mesh side pockets

• Water-tight roll top closure

• Stuff sack included

• Best activities: summit chasing/day hiking/travel