The Hohner Blues Blaster is not intended to be used as an actual harmonica microphone. It does, however, make for a very pretty stage prop or a clean shell to completely rewire with $100 worth of vintage hardware. The shell and grill are rather fetching, but even the screws holding those two pieces together are soft in a bad way.
Instead of the volume knob being up front for a thumb to lightly turn, it's in the back and tight enough to need two fingers. The XLR jack is lightly glued in place instead of being threaded to washers. And the included 6' XLR-to-1/4" cable is the sort of thing that should surely short out within a few months of regular use.
The Japanese-made crystal element is small, cheap and padded in the front with equally thrifty materials. Its frequency response does happen to pick up higher notes better than classic harmonica microphone elements, but that doesn't matter because the overall response is weak; you aren't ever going to get that Chicago "honk" tone with just this thing and an amp.
In the end, including the original price of this cheap mic, it will cost me the $200-250 you'd pay on eBay for a nice pro-built mic, for me to rebuild this one myself. Even if you're into learning how to build harmonica microphones, you could pay a lot less than this for a pretty shell and chrome grill; everything else about this microphone is cheap and/or ill-conceived.