Sharps Bros. SBLR07, Gen 2 Overthrow (Spartan Helmet Design), Semi-automatic, Billet Lower Receiver, 223 Rem/556NATO, Black Finish, CNC Machined from 7075 Billet Aluminum SBLR07 This, my friends, is Overthrow. An open mag well helmet design, with battle worn dents, sword gashes and crack lines. Leave it anodized black, give it a Spartan style, a Viking theme ... the customization opportunities with this one are endless.