Silverplate, enamel. 23mm x 19mm. Well made. Shows Lenin's portrait and the number "100" repeated behind him.
Very fine condition. Some very minor wear to front edge of Lenin's face and the plating has tarnished in places.
One of the better designed pins made to wear during the year-long 1970 celebrations. Lacking an imprinted price, it was probably not one of the badges ("znachki") available for purchase in stores or Soyuzpechat' kiosks but designed to given notable attendees.