Shure SM81 is a high-quality, cardioid condenser microphone designed
for studio recording, broadcasting, and sound reinforcement and
its wide frequency response and low noise characteristics have
established it as a standard for applications involving acoustic
instruments, especially strings, piano, and cymbals. It gives
a pretty faithful reproduction of whatever you point it at and
you can use it for vocals though it is very sensitive to plosives.
To be fair, the mike probably wasn't really designed for voice
work, but you can get round the problem using a good pop shield.
The mic also has a three position low frequency roll off and attenuation
switches making it a pretty versatile performer.