This pin is in good condition. Bratislava was a major city in Czechoslovakia when it turned to communism in 1947. Now it is the capital of Slovakia.
The pin says:”Nationwide summer championships SNB”. So the pin has something to do with sports, probably championships amounst SNB members.
The SNB (Sbor národní bezpečnost) was the nationwide security corps or police from 1945 until 1991 when Czechoslovakia was under communist rule. The SNB was closely related to the militairy. The SNB was abolished and replaced by the Czech Police on July 15, 1991, following the Velvet Revolution of 1989 in which the SNB attempted to suppress the demonstrating students.