Panasonic Model R-72 novelty AM transistor radio.  Toot-A-Loop Radio - $30.00     Donut shaped radio can be worn as a bangle around the wrist or twisted into an 'S' shape to be free standing. The tuning dial is located at the end of one of the 'splits' accessed when the radio is twisted into the 'S' shape. The on/off and volume control is located on the outer edge of the unit as is the earphone jack. The case of the radio is molded from impact resistant ABS plastic and has a characteristic high shine finish. This AM radio works good but the volume knob is sensitive when changing the volume.  Uses one 9 volt transistor battery.  New in 1973 as a birthday present.                               If you are unfamiliar with the value of these vintage radios, do a search on Ebay and you will see they are valued at $90.00 to $120.00. 

https://en.wikipedia.org/wiki/Panasonic_Toot-a-Loop_Radio