DC has updated their Diamond listing for Flash #38 B from artist Howard Porter and replaced the cover with a beautiful Francesco Mattina cover. You can check out this Killer B below.
Not an exclusive, not a store variant, but an honest-to-goodness Mattina B cover.
Retailers like TFAW, Midtown, and Mycomicshop have not updated their listings yet, from the Porter cover to the Mattina cover, but they will before the 1/10/18 shipping date.
The Flash #38 B can be pre-ordered now.