The Armsel Striker, Armsel Protecta, or DAO-12, is a South African revolver-like shotgun designed by Hilton Walker of the Sentinel Arms Company, originally stationed in Rhodesia (now Zimbabwe). With the original design having flaws, Walker redesigned the weapon in the 1980s, resulting in the Protecta/Street Sweeper model that has found its way around the world today. DAO-12 is short for Double Action Only 12 gauge, referring to the weapon's operation and caliber.