Also, the FT Derringer V3 clone top caps and inner sleeves (although I think all versions of the FT Derringer clones do) fit on that Hastur base. I have both the Derringer V3 and this Hastur V2 and confirm that they do. You can buy the Derringer top cap and sleeve separately at FT too.
$2.75 Replacement Stainless Steel Top Cap for Derringer RDA Atomizer - black at FastTech - Worldwide Free Shipping
$1.52 Replacement Inner Sleeve for Derringer RDA Atomizer - stainless steel at FastTech - Worldwide Free Shipping
Thanks for this tip. I have both and will try it. I like the Hastur V2 deck. But suspect the more direct side air from Derringer will improve the flavor.
Not sure how you got the Derringer cap to work on Hastur V2. It's nowhere near tall enough to clear the Velocity posts.