Stop the Show Trials -- Vintage [Pinback]
No printer, place or date. 1 1/2" in diameter. Locking pin style back.
The assumption is that this paticular pinback references the trials of various Black Panther leaders and other US political prisoners in the late 1960s and early 1970s GOOD; printing on the face slightly off center, minor fading, rear a bit tarnished, with the remains of a small circular sticker present.