This Soviet badge represents the elite Soviet Guards detachments. Which have their origin in the Great Patriotic War (1941-1945), the Soviet-German phase of WWII. Guards were formed from units that showed extraordinary heroism in combat. This tradition was carried on into the post-war era. as a term for most elite and legacy units.
Notably this particular variant was issued from the 1970-1980s. And is among the higher quality of Guards' badges. It's dimensions are 47 x 38 mm or 1.85 x 1.50 in, constructed from cast brass and enamel. Removing the badge's back screw, reveals it was produced by the Moscow Mint.