I have a Yoga DM-330B dynamic mic

Questions:
I can't find any info on it....is it any good ? I know it is horses for
courses with mics. What might this one be useful for ?

Can anyone point me to a spec ?

For some reason, XLR shield (pin1) is internally connected to one of the
outputs. The only way I can get reasonable noise/hum levels is to disconnect
the shield connection in the mic.cable XLR connector at the mic. end. Why
have they done this to what I thought should be a balanced output ?

To avoid having to use a modified mic. cable would it be a good idea to open
it up and remove this internal connection ?