Maybe they got some overseas releases that they are selling? I didn't see them on the Official HammerBowling website earlier. Whatever it is though, they wouldn't be selling it if there wasn't a demand for it. I'll stick with my Black Widow Legend that I just ordered 
This looks to be a private pouring, like the Green Vibe they had made. Nothing I'm seeing released overseas on this; not even with the cover.
But looking at it, it's a solid, so I don't know if it would be safe to compare it to the BW Assassin.. Though I wonder how it will react with that final 1500 Abranet finish on it after the 500/500/500/1000 Abralon.
That RG and Diff...
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Last time they had that was on those Int'l Taboo Limiteds from Japan.
It might be safe to slot this (barely) between the BW Legend and BW Assassin.
BL.