This is a factory Spike's Tactical AR-15 lower receiver. Called the "Viking" this lower has a unique theme, that features a Viking Skull. For the selector switch instead of safe, semi, full auto the lower has "Trur (Safe, other meanings: Trust, Think), Fleygja (Fire, other meanings:: Fling, Throw), Orviti (Madness, other meanings: Idiot, Stupid, Crazy)".
