the missing blue band around the grill is a common occurrence in fake Shure microphones because they slid off so easily unlike the real ones that are sturdy. although that doesnt mean these mics are counterfeit automatically.
the sound quality is very close so its really hard to tell. however, there is much handling noise on the fake ones.
so you may ask, why, if it sounds and performs close to a genuine SHURE, must we know if its fake or not.
if youre told you were buying a SHURE and youre paying for a SHURE, you damn should get a SHURE.
however, there is no shure (pun) fire way to know for sure but lets feature what you should see in a genuine SHURE microphone.
http://www.youtube.com/watch?v=nIaphYCox20