Magpul has announced their new MBUS PRO backup iron sights. Surprisingly these sights are constructed of steel, not the polymer that Magpul is famous for. The added durability of an all-steel construction comes at a cost. The rear and pro sights are about twice as expensive as their polymer cousins. The rear sight has an MSRP of $104.95 and the front sight has a MSRP of $84.95.