The Toot-a-Loop Radio or Panasonic R-72 is a novelty radio made by Panasonic Japan in the early 1970s. This radio was designed to be wrapped around the wrist (provided your wrist wasn’t too large).
Reception is the AM broadcast band only – no FM. Radio is shaped something like a donut with the hole off center. If twisted, the smaller half pivots and the larger half separates, forming an “S” shape. One side of the radio has a grill behind whith the speaker. There is also a jack for a mono earplug. The tuner is located inside one of the “splits” so the radio has to be twisted into the “S” position in order to be tuned, but the volume control is the outer diameter of the radio and can be adjusted regardless of whether the radio is twisted open or closed.