Peak Design's 7L Outdoor Sling can be used with the XS Camera Cube, though the smallest 2L Outdoor Sling is too small to fit any of the cubes and is better suited to smaller accessories.

The 15L version can hold a DSLR with lens attached, and a few extra lenses or accessories while ... you need more kit than just a camera and one lens. The Peak Design Everyday Backpack Zip 15L ...

Peak Design Camera Cube V2 There aren't any pockets or zippered sections for small accessories, but the cubes do come with a single 'floating packet' a mesh material bag that can be Velcroed onto ...