Sometimes a bolt pistol won't cut it. Neither will a bolt gun. Sure, it essentially fires out little rockets, but they're little rockets. Sometimes you just need a weapon that can put a hole the size of manhole cover in even the thickest armor and then cause whatever you just shot at to explode spectacularly. That's when the really heavy weapons come out, and when you form groups of psychos crazy enough to fire these weapons in one place, you get Devastator Squads. And GW's taking pre-orders for the new version of them.
As always, the kit comes with something like a hundred thousand ways you could potentially arm your little mans. There's two of each heavy weapon (Grav-Cannon, Missile Launcher, Multi-Melta, Lascannon, Plasma Cannon, and Heavy Bolter), as well as 15 different weapons to arm your sergeant (just pick something you might want him to have and chances are pretty good the option's in there). There's also various various extra helmets, legs, hands and arms, plus pieces just for accents like purity seals or spent shell casings.