That looks like the MFJ-283 I tried, although quite a bit cheaper. I was not impressed with the MFJ, the ear mic didn't sound good although the ear phone part was OK. In any case I had to put a piece of tape over it to keep it in my ear, the fit is sorta weird. To work they have to sit down in your ear canal fairly far. This is sorta blocky and the curve didn't follow my ear, but it was also not very supple and didn't conform and would pop out.
So I'll be curious to see if you find the same things I did. If not and this one works better, $20 is MUCH easier to take.
FWIW, the bone conduction mic concept does seem to work, the signal reports I got weren't any worse while riding than while standing still. I was told I was unreadable, very narrow response. I wondered if I had the right PTT circuit, it must measure 2K between the mic line and ground with the PTT pressed to work. If this is built wrong it will cause bad audio, but I didn't want to throw away $40 opening the little box to see and I ended up sending it back to MFJ. :-(
The ones I've seen from Motorola, bone conducting mic ones I mean, work well. But they cost a couple of hundred to a few hundred dollars. These are typically used by first responders and military when they're wearing SCUBA gear or otherwise would have their faces covered. Plus they are waterproof.
"Why does the U.S. care which flag will be hoisted on a small piece of land thousands of miles away?" -- Ron Paul