Bum bag by Herschel Supply Co, For those just-in-case necessities, Adjustable body strap, Secure clasp fastening, Zip closure, External pocket, Contrast detail, Herschel logo detail, Holds up to 3.5 litres. Herschel Supply Co produces quality built backpacks inspired by vintage mountaineering equipment, American heritage and world travel. With a passion for individuality and personal style, Herschel Supply Co adapts to a new generation updating their bags with a modern fit, shape and feel.