Bum bag by ASOS 4505, Your new running buddy, Adjustable body strap, Secure clasp fastening, Branded detail, External pocket, Zip closure, Can fits an iPhone XR. The new activewear range from ASOS offers high-quality gear whatever your workout. Whether you're gaining or training, ASOS 4505 has the very best performance kit, cut to keep you cool, dry and fly. Reflecting your personal style to ensure your playtime has personality, this is our movement for movement.