I just got reply from GD, They say this one is their product, but didn't say how they made it.
I think FairwayFred is right about it. This looks like shot-peened process, just don't know why they did this to wedge, is that any good?
Actury, I am still waiting for seller to ship this wedge to me, so I havn't try it. will report to here after I get it.
BTW, I have sent an email to Gauge Design, but no return utill now.