Bum bag by Calvin Klein Jeans, New bag, new outlook, Adjustable body strap, Secure clasp fastening, Branded design, Represent, Zip closure. With a company history spanning back to 1968, Calvin Klein originally started life as a coat store in New York City. The now iconic label, famed for their minimalist approach, offers up covetable diffusion lines CK by Calvin Klein and Calvin Klein Jeans, both of which channel the label's inimitable style.