I have two Shure mikes that look identical to SM57s except they don't say SM57 on them. They do say PE66L on them but not in a way that sticks out. I think they might be older because Shure is written slightly different. The letters are red and not slanted like they are on my 58s (which are 12 years old themselves). Also, the metal screen on the end is black, not silver, like all the 57s I've seen. Are they 57s? Anybody know what they are and how they compare?
